PY Online Forums - Bringing the Pontiac Hobby Together - Pontiac - Street https://forums.maxperformanceinc.com/forums/ No question too basic here! en Tue, 21 Jul 2026 13:37:21 GMT vBulletin 60 https://forums.maxperformanceinc.com/forums/images/SultanThemeVB3R/misc/rss.jpg PY Online Forums - Bringing the Pontiac Hobby Together - Pontiac - Street https://forums.maxperformanceinc.com/forums/ Voltage low at resistor wire https://forums.maxperformanceinc.com/forums/showthread.php?t=886348&goto=newpost Mon, 20 Jul 2026 22:04:57 GMT OK-disclaimer. I hate electrical and am a dimwit when dealing with it, but forging my way through. I figured I’d post here even though this is on a friend’s ‘61 Olds Cutlass with stock points ignition, I figured the theory is the same.
Car has spark, fires, but not starting. Fresh points, plugs, condenser. Keeps fouling plugs out.
Thinking maybe I have a spark, but maybe too weak, I dug further into the ignition.
1.5 ohms on primary side of coil, that looks to be in spec.
7100 on secondary side, that appears to be a bit on the low side according to specs for a ‘61 Cutlass 215 V8
I’m showing 5.1-5.2 volts at positive side of coil with key in the run position. I read that it should be 7-9, and that 5 could cause a weak spark.
I don’t have his shop manual in front of me, and he’s out of town, so I’m relying on the internet for these specs. BTW.
I don’t want to throw parts and money at it, so just wondering if these readings are far off enough to cause a spark but no start condition?
Also, can I temporarily hook 12 volts to the positive side to see if it runs, or will the points burn up that fast?
Thanks ]]> Pontiac - Street 67drake https://forums.maxperformanceinc.com/forums/showthread.php?t=886348 The fixes for the big and smaller problems of early Edelbrock chambers https://forums.maxperformanceinc.com/forums/showthread.php?t=886333&goto=newpost Sun, 19 Jul 2026 18:00:17 GMT I meant to post this info a good while ago and I just got my iPad going again to get at these photos off it. The early Edelbrock chambers have a major machining issue in that when the corners of the chambers get machined by two different cutters they, number 1 leave a bad recessed area ( fuel... I meant to post this info a good while ago and I just got my iPad going again to get at these photos off it.

The early Edelbrock chambers have a major machining issue in that when the corners of the chambers get machined by two different cutters they, number 1 leave a bad recessed area ( fuel collection pocket)
and 2) leave very sharp edges that make for local hot spots.

These two recessed areas collect fuel that does not light off when the spark lights off the main pocket of air and fuel mixture in the chamber.

These two pockets of unburned fuel either get sent out the exh as wasted fuel, or worse yet (when the temperature gets hot enough to do such ) finally light off late in the burn of the main pocket and then these two colliding flame fronts create a power loss and destruction as in detonation.

In my seperate photos of the stock chamber in these two locations you will see that these two
Pockets I have colored up in black marker .

You can also see the sharp machining edges left also.

There is a particularly bad lip left on the corner of the intake valve that stands up close to .050” and very close to the edge of the valve

There are other restriction and sharp edges around both valves on the shallow side of the chamber that I will make a separate post about.

Mean while grinding and then polishing out these areas on the plug side of the chamber takes the use of some special cutters and a good portion of the material removal and polishing can only be done with the nose of a lot of tapered sanding rolls, and of course with sacrificial valves in place .

Although even then a few areas that needed rework of both valves I found I could only get these areas done without having the protective valves in place, and all of this highly tedious work took me near 3 hours to get the 8 chambers done.

One of my photos shows the ruff cutting with no blending polish done yet.

I hope these photos work well with my info above here, but for certain these two dimensional photos do not show the severity of these two fuel collection pockets left as Edelbrock shipped these stock.
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]]> Pontiac - Street steve25 https://forums.maxperformanceinc.com/forums/showthread.php?t=886333 Should Rally II wheels be lug balanced? https://forums.maxperformanceinc.com/forums/showthread.php?t=886332&goto=newpost Sun, 19 Jul 2026 17:29:37 GMT I have just finished blasting, masking and painting some Rally II wheels for my 68 Bonneville. I have read that Rally II wheels are lug centric and not hub centric. Is that really the case? In the past I was unaware of any difference and just let the tire shop have at it with the central... I have just finished blasting, masking and painting some Rally II wheels for my 68 Bonneville. I have read that Rally II wheels are lug centric and not hub centric. Is that really the case?

In the past I was unaware of any difference and just let the tire shop have at it with the central balancing cone. Before I have the tires swapped to the freshly repainted set of wheels, do the Rally II really need to be lug centered? I have called around and while the local shops are familiar with the terms hub centric and lug centric, none of them perform pin balancing and don't have a 5 x 5 pin plate. How is everyone out there approaching this?

I have also read about buying a 5x5 wheel spacer and asking the tire shop to try using the spacer as an adaptor. Again, is this really necessary?

Thank in advance for any help! ]]> Pontiac - Street rustyrelic https://forums.maxperformanceinc.com/forums/showthread.php?t=886332 428 Swap update: done! https://forums.maxperformanceinc.com/forums/showthread.php?t=886327&goto=newpost Sat, 18 Jul 2026 11:35:09 GMT Well I’m proud to say the 69 bird 350-428 swap is done. Mostly. With considerable help from many here the deed is done. Many battles were fought. I had never done anything like this. I have learned an incredible amount! I ended up putting in my old points distributor and shelving the HEI for... Well I’m proud to say the 69 bird 350-428 swap is done. Mostly.

With considerable help from many here the deed is done. Many battles were fought. I had never done anything like this. I have learned an incredible amount!

I ended up putting in my old points distributor and shelving the HEI for now. I struggled to get it right. But I’ll go back to it. Set initial timing to 12 deg.

I installed my original th350 after a rebuild and upgrade. Added braided lines and a new shift cable.

Installed new cold case radiator. I was very impressed with the fit. Factory shroud fit perfectly. 7 blade clutch fan. I installed a temp gauge just to make sure things are cooling. Running at 170 on 90 deg day! Haven’t hit 190 yet.

Alternator is charging 14 volts.

Starter is struggling to spin the high compression 428 but it goes. Probably an upgrade in future. Engine fires nearly immediately. Replaced pos cable with 0 awg.

Qjet is doing ok. Not sure it’s opening up fully. My throttle cable is a bit short and yankee engineered. But…

Hooked up old single exhaust just to run. New dual going in next week!

Still running grocery gears. Rear end upgrade coming.

Thanks again for the help of so many great people!!
She goes!! ]]> Pontiac - Street hgiv https://forums.maxperformanceinc.com/forums/showthread.php?t=886327 Q-Jet acceleration Question https://forums.maxperformanceinc.com/forums/showthread.php?t=886313&goto=newpost Fri, 17 Jul 2026 15:18:27 GMT So, my 455HO (470cid) runs great, get about 15mpg when drive easy. But when hard accel, say from 30mph, Pull out pass someone, WOT itll starve for fuel after a second. Then kinda come back, If I ease off a little, she fine. Also, If I slowly ease into her, she fine all way up to top speed,... So, my 455HO (470cid) runs great, get about 15mpg when drive easy. But when hard accel, say from 30mph, Pull out pass someone, WOT itll starve for fuel after a second. Then kinda come back, If I ease off a little, she fine.
Also, If I slowly ease into her, she fine all way up to top speed, 6000RPM for long Hwy run. AKA, dusting that BMW who thought he was fast on the 2 mile straight.

I have Elec fuel pump, Holley Blue, and a .110" inlet seat.
Would you think its the small inlet seat not letting enough in when I really accel hard? Letting bowl drop and fuel slosh to uncover jets? Ir pump not keeping up to the acceleration demands?

Only happens on a Hard launch or accel when there lots of 'push you into the seat' G forces.
I can burnout for days no issues either ]]> Pontiac - Street zippy https://forums.maxperformanceinc.com/forums/showthread.php?t=886313 WIre gauge for HEI and starter solenoid https://forums.maxperformanceinc.com/forums/showthread.php?t=886312&goto=newpost Fri, 17 Jul 2026 13:36:32 GMT Wiring a run stand what size should I use for both of these, as well as fuse amperage. Figured more traffic here than Electrical folder Wiring a run stand what size should I use for both of these, as well as fuse amperage. Figured more traffic here than Electrical folder ]]> Pontiac - Street Skip Fix https://forums.maxperformanceinc.com/forums/showthread.php?t=886312 <![CDATA[Rally2 10"" rim]]> https://forums.maxperformanceinc.com/forums/showthread.php?t=886299&goto=newpost Thu, 16 Jul 2026 20:17:11 GMT What is the backspacing on these 10" rims,is it 4 1/2 or 5""?...Thanks in advance ]]> Pontiac - Street joes455 https://forums.maxperformanceinc.com/forums/showthread.php?t=886299 New dyno results old 400 https://forums.maxperformanceinc.com/forums/showthread.php?t=886289&goto=newpost Thu, 16 Jul 2026 01:02:46 GMT Got off the dyno with a 400 built with the plan of mainly extra parts laying around for the 65 GTO stick car so it moves on its own in place of the barely running original 389 4BBL. Short block the 0.0303 400 557 block I had under the RAIV heads racing NMCA for years. TRW 2262s/pressed pin... Got off the dyno with a 400 built with the plan of mainly extra parts laying around for the 65 GTO stick car so it moves on its own in place of the barely running original 389 4BBL.

Short block the 0.0303 400 557 block I had under the RAIV heads racing NMCA for years. TRW 2262s/pressed pin Crower billet rods. Clean up hone and tanked. Had to turn crank 0.020 to get some bearing close in clearances and not too loose . Still about 0.0028-0.003 mains and rods. 5/64 rings for the TRWs limit choices. Standard 0.030 Sealed power "drop in" were 0.028 top ting and 0.020 second ring. File to fits were way too much tension so went with the first set. one piston was 0.008 out another 0.005 so went with the thicker regular Butler head gaskets-added the "421 hole".

Heads some new "72" cc E heads Paul Knappen cleaned up , clearances for 1.65 rockers. Original "bathtub" chambers. Paul used the Comp 917 springs Polydyun coated I had bought years ago for my first E heads(on the IA now but were on the roller 455 years ago) they were tight on those pockets so those heads got some Lunati 1.500 springs). 1.65 Crower SS rockers I picked up here years ago. 9.300 Comp 5.16 pushrods.

Comp solid rollers I had ton the roller 455 years ago-non pin oiled. UD/Bullet solid roller from the .3707 lobe family to use the high ratio rockers. 242/249@ 0.050 112 LS 108 IC. Felt the 259/264 .3707 for the 455 would be too rowdy in a 400 even being a stick. Tim at Bullet and I talked a awhile and he agreed with my choice.

Intake an older Performer RPM I lended to Lee year ago to try on his Firebird vas a T2. Cut out the exhaust crossover and front part to water crossover to look like a tal HO intake. Ground off Edelbrock and bead blasted it.

Oil pan deep Moroso GTO pan that came with the 455 when I bought it. Braces and teflon coated full length factory windage tray originally on the RAIV motor.

Carbs to try:
1)HP 950 off the recent 455 Stump Puller since I new it worked. 83/89 jets
2)HP 750 body and new 750 DP metering blocks, bowls and baseplate I had extra 72/81 jets(out of 80s)
3) Demon that started out as an 850 Jeff "Shaker 455" machined for the demon changeable sleeves. Was run on the IA motor years ago with big sleeves I put in the "Red" ones between a 750 and a 850/950/1000(all the same size really) I must have tweaked something pulling the baseplate off and on for them as we could not get it to idle at all and gave up on it.
4) 73 SD SR Qjet first massged by Brad Urban with larger primary blades and replaceable secondly jets Then Cliff went through it a few years back. 71 rods/44 jets and DA secondary rods on a B hanger.

Headers -my trusty 2" Hooker 4202s and the tribal Tubes 1 3/4-1/78 tri Ys. Had some OBX 1 7/8 but just did not try them.

Weather cool and overcast for Houston summer high humidity and started drizzling mid day.

The RobbcMc starter used on the 455 did not sounds right -probably just needed shimming but threw on and extra McLeod but had to trim the pan rail for it some clearance where the bolts stick out.

results 950 HP Best TQ 478 @4100 HP 484 @5900 kind of fat BSFC.
750 HP TQ 477 @3800 HP 470 @6100
Qjet TQ 476 @4000,4400,4600 HP 474.9 @5800

Tri Y Qjet TQ 479 @4200-4300 HP467 @6000 and a 114% VE @4000. We only had the VE hat on for the Q jet pulls.

Best thing was no oil leaks!!!
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]]> Pontiac - Street Skip Fix https://forums.maxperformanceinc.com/forums/showthread.php?t=886289 Engine Balance Question https://forums.maxperformanceinc.com/forums/showthread.php?t=886279&goto=newpost Tue, 14 Jul 2026 23:20:02 GMT I have been led to believe forever that Pontiac engines were internally balanced, now that I am getting ready to balance and assemble my short block I researched parts and discovered there is more to this than I thought. I have not purchased a flexplate or balancer yet so my question leans on what... I have been led to believe forever that Pontiac engines were internally balanced, now that I am getting ready to balance and assemble my short block I researched parts and discovered there is more to this than I thought. I have not purchased a flexplate or balancer yet so my question leans on what flexplate to purchase - internal or external balance?

I know, in order to answer that you need more information on my short block - I have a .030 over early 75 (481988) 400 block with a stock early 1970's 400 crank. I L2262F30 Speed Pro forged pistons (heavy I know) and Eagle 6.625" 5140 I-Beam rods. My understanding from information I could find is the pistons are close in weight to the stock cast pistons and the rods are slightly lighter than stock cast rods.

When complete, this will be in my 1974 Grand Prix mainly for cruising and shows. The car will have a 200-4R overdrive and 3.73 gears (maybe 3.42 gears if I eliminate the torque converter lock-up. If I planned on running it hard, I would use a better forged piston but feel the L2262F's should be plenty strong for how I plan on using the car.

My gut says I should use the external balance flex plate, no matter what I do I will have it professionally balanced. I just want to avoid adding heavy metal to the counterweights if possible - it really add to the cost of the balance job! Thanks. for your responses up front. Tom ]]> Pontiac - Street Iggy https://forums.maxperformanceinc.com/forums/showthread.php?t=886279 Convertible top https://forums.maxperformanceinc.com/forums/showthread.php?t=886269&goto=newpost Tue, 14 Jul 2026 15:16:52 GMT What is a good convertible top brand. anyone have experience with Easy-on? Also was the factory top window glass or plastic. Thanks What is a good convertible top brand. anyone have experience with Easy-on?
Also was the factory top window glass or plastic.
Thanks ]]> Pontiac - Street GoGoat https://forums.maxperformanceinc.com/forums/showthread.php?t=886269 Painting iron heads on 400 engine https://forums.maxperformanceinc.com/forums/showthread.php?t=886266&goto=newpost Tue, 14 Jul 2026 13:59:27 GMT I rarely build an engine, but the Pontiac engines I have done, I've always mounted the iron heads and valley pan, then taped off the machined surface of the heads that the intake mates to. I then paint the non-taped area on the intake side of the heads along with the valley pan before attaching the intake. The same goes for the iron intake manifold. I had always kept it bare metal on the machined surface. It's only recently that I read it's okay to paint the machined surface of the intake as long as no paint gets inside the ports.

That begs the question of whether or not painting the heads mating surface for the intake would also work. It would be much easier than taping everything off and I would think it would also help prevent rust from creeping out from the edges of the gasket.

I can see many arguments for not painting these surfaces, yet I see posts in other forums where people say they have done it with no issues.

I appreciate hearing from those of you that have experience painting these areas and what the results were (are). If you have successfully done this, I appreciate any tips such as whether or not certain intake gaskets work better on these painted surfaces than others. Once this engine is done, it likely won't be cracked open again in my lifetime so I'm not worried if painting these surfaces makes it hard to get these areas clean again if the intake is removed.

BTW, no need to get into discussions about paint burning off the outside of the exhaust ports. I have plenty of bad :( experiences with that and how to make it better with high temp paint :) in that area before painting the Pontiac Blue.

Thanks
Old Joe ]]> Pontiac - Street gtobird https://forums.maxperformanceinc.com/forums/showthread.php?t=886266 Franken engine dipstick https://forums.maxperformanceinc.com/forums/showthread.php?t=886247&goto=newpost Mon, 13 Jul 2026 03:17:55 GMT My dipstick is most likely incorrect.... I've read the engine takes 7 quarts with filter
Is that correct? I'll mark it correctly at the next oil change.
74 455

George ]]> Pontiac - Street george kujanski https://forums.maxperformanceinc.com/forums/showthread.php?t=886247 Factory replacement coil? https://forums.maxperformanceinc.com/forums/showthread.php?t=886231&goto=newpost Sun, 12 Jul 2026 03:35:57 GMT 70 T/A 4-speed

Stock 400

Replaced the points with a Breakerless SE kit about 5 years ago and it's been great

Crisp starts and I haven't had to touch the timing since the install

That being said, I was leaving OSW earlier tonight and noticed a bit of a stumble when accelerating.

Pulled off into an open parking and she died.

Cranked her up and she started, but had a severe misfire like she was running on 4 cylinders, then she died again.

Popped the hood and noticed the coil was hot to the touch

Checked the ring terminals best I could (it was already dark), but they felt tight.

Pulled the coil wire and it was also fine.

Let her cool for about 15 minutes, then fired her up and she was good to go again like nuthin ever happened.

Hauled ass home and powershifted through the gears without issue.

Have yet to check coil resistance, but I figure I better pickup a spare regardless.

Thing is, I remember when I was installing the Breakerless kit that they suggested only using a factory spec coil and not an MSD or Accel.

What would be the best stock appearing coil that's compatible with the Breakerless module? (I believe it's like 1.3ohm or so) ]]> Pontiac - Street 98 SNAKE EATER https://forums.maxperformanceinc.com/forums/showthread.php?t=886231 Fuel filter bracket https://forums.maxperformanceinc.com/forums/showthread.php?t=886221&goto=newpost Sat, 11 Jul 2026 04:30:38 GMT Where does the fuel filter bracket mount on a 1964 full size Pontiac that uses a filter with a return line? I’m trying to install a return line on a car that never had one. I know it mounts beside the timing cover but it doesn’t seem to fit on any of the bolts. Also where does the little tab for... Where does the fuel filter bracket mount on a 1964 full size Pontiac that uses a filter with a return line? I’m trying to install a return line on a car that never had one. I know it mounts beside the timing cover but it doesn’t seem to fit on any of the bolts. Also where does the little tab for the return line from the filter attach? Thanks. ]]> Pontiac - Street Goatracer1 https://forums.maxperformanceinc.com/forums/showthread.php?t=886221 Mahle pistons https://forums.maxperformanceinc.com/forums/showthread.php?t=886207&goto=newpost Thu, 09 Jul 2026 11:38:59 GMT Just wondering if anyone has any experience with Mahle pistons on the street that have the 1mm 1mm 2mm ring pack. Any blow by issues after lots of miles? Just wondering if anyone has any experience with Mahle pistons on the street that have the 1mm 1mm 2mm ring pack. Any blow by issues after lots of miles? ]]> Pontiac - Street slowbird https://forums.maxperformanceinc.com/forums/showthread.php?t=886207