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-   70-72 GTO Tempest & LeMans TECH (https://forums.maxperformanceinc.com/forums/forumdisplay.php?f=436)
-   -   '71 455 HO GT-37 Journey Begins (https://forums.maxperformanceinc.com/forums/showthread.php?t=790693)

SD455DJ 05-24-2020 12:21 PM

Quote:

Originally Posted by Mike Kasparian,Sr. (Post 6144099)
I don't know if it's legal for your racing but do you know of anybody that used manifolds that have been prepared using extrune hone ? Probably not worth much with lower rpm but I thought I read somewhere that it was being used in factory type racing classes . I don't know how you guys do it on those little bias tires . Really cool

Mike - We don't allow modified, or aftermarket 'enhanced', exhaust manifolds at the Pure Stock Drags, but they are allowed at the F.A.S.T. races. We don't check, or tear down engines, but I'm sure a lot of the Pontiac guys are running the RARE 2.5 RA manifolds and the 'log' manifold cars have been opened up a bit, not to mention extrude honed. For the tenth and couple mph they give you, we don't get too excited about it any more. The 2.5" mandrel bent systems we allow drop ET's more than opened up manifolds. The repop Wide Ovals and Polyglas's are stickier than the originals and we 'glue' the track regularly to allow 1.8 sec 60' times with the cars that are prepared. We don't allow 90/10 shocks on the front, but I see a lot of empty front shocks and spaced sway bars (allowed). You have to learn how to just be on the verge of wheel spin when launching and that is a true craft to master and be consistent at.

Dennis

Mike Kasparian,Sr. 05-24-2020 03:25 PM

If there is a way too get an advantage in class racing guys will usually figure it out . I used to race NMCA back in the 80s and that was alot of fun before it got out of hand . Respect for your factory style racing .

scott70 05-24-2020 09:35 PM

I dynoed my # 64 headed 455 with 1 3/4" hooker headers and then switched to RA manifolds with 2.25 outlet dumping into 2.5" mandrel bent headpipes. About 18 HP and tq. difference.

SD455DJ 05-25-2020 01:55 PM

Scott70 - I imagine the hp/tq difference between RA manifolds and headers would be 30 +/- when the carb is richened up to cover the lean condition headers cause. Did you richen the carb when you swapped over to headers?

Dennis

scott70 05-25-2020 09:16 PM

We did not. Comparing dyno AFR and BSFC numbers between headers and manifolds the differences was very, very small. 19 hp and 6 ft.lb peak difference. Using my 7040267 carb by Cliff. Ive had people tell me they even had less hp difference than me swapping between the 2 exhausts .

SD455DJ 05-25-2020 09:38 PM

scott70 - That is interesting the minimal difference in power, speaks to the efficiency of the 2.5" RA manifolds with the total combination.

Dennis

scott70 05-26-2020 10:40 AM

Of course this is on a 490hp/570 trq motor. If it were making more power ,the demand for better airflow/less restriction is needed and the differences would be larger I believe. Ive always been impressed by your cars.

SD455DJ 05-31-2020 04:16 PM

Quote:

Originally Posted by scott70 (Post 6144702)
Of course this is on a 490hp/570 trq motor. If it were making more power ,the demand for better airflow/less restriction is needed and the differences would be larger I believe. Ive always been impressed by your cars.

Thanks Scott...We know we left a lot of HP on the table, but this is a Pure Stock Drags type build and the 2802 cam is mild enough to make 18 in. vacuum at 1200 rpm unloaded, so allowed by the rules. If it had max allowed 9.9 compression and the 2.5" outlet RA manifolds, it would have made 450 hp and 550 lbft torque easy.

Dennis

SD455DJ 07-28-2020 05:33 PM

The GT-37 is now back on-deck to focus my energies on. We are going to work on the brakes and suspension to check condition and repairs/upgrades where needed. The 455 HO (average dyno pulls of 425 hp/535 lbft torque) will be installed with the big 455 motor mounts and backed by the BW-ST10 (2.64 1st gear). We may have a one piece A-body driveshaft in the stash, but, if not, will have to have a custom one made for it. The 12-bolt McKinnon 3.31 gears are original and will get a visual check for any issues (don't anticipate any). I need to send/deliver the instrument cluster (factory gauges) to Bob's Speedometer to rebuild them before I can reinstall the assembled dash.

There isn't a headliner in the car, but may have to install one later. This is going to be the muscle car version of a rat-rod with patina galore, but I want to get it back on the streets. I don't think I can get the RR quarter fixed and the trunk floor replaced on my schedule...but that can happen after the car is drivable.

Dennis

SD455DJ 08-11-2020 07:13 AM

The Rally gauges are a Bob's Speedometer in Howell, MI getting the work-over...the fuel gauge lost its fluid(?) and getting new installed and recalibrated, the oil and water temp are getting rebuilt and recalibrated, and the speedo is getting totally rebuilt since there is no trace of lubrication (hey, it's only 49 years old) and squealed like a stuck pig when tested on their machine. They should be ready to pick up next week...then the dash can get put together and reinstalled in the interior. The hood tach is a new unit from Randy Combs, so looking forward to the gauges working like new.

Dennis

Uncle Judge 08-11-2020 09:32 AM

Quote:

Originally Posted by SD455DJ (Post 6168602)
The Rally gauges are a Bob's Speedometer in Howell, MI getting the work-over...the fuel gauge lost its fluid(?) and getting new installed and recalibrated, the oil and water temp are getting rebuilt and recalibrated, and the speedo is getting totally rebuilt since there is no trace of lubrication (hey, it's only 49 years old) and squealed like a stuck pig when tested on their machine. They should be ready to pick up next week...then the dash can get put together and reinstalled in the interior. The hood tach is a new unit from Randy Combs, so looking forward to the gauges working like new.

Dennis

Hi Dennis. Sounds like some nice progress. Did you mean Randy Watson on the Hood Tach ?

SD455DJ 08-11-2020 09:59 AM

Quote:

Originally Posted by Uncle Judge (Post 6168627)
Hi Dennis. Sounds like some nice progress. Did you mean Randy Watson on the Hood Tach ?

Ugh! Yes, Randy Watson....total brain fart on my part! Thanks Jeff! I really need to make better progress on it this fall...this poor car has been relegated to the back seat too many times...no more new cars to get in the way!

Dennis

SD455DJ 08-19-2020 07:10 AM

The gauges are done (2-week turn around) and we're picking them up this Friday along with the PQ tranny for the Formula, so that will allow work on the old GT-37 to start once again (that should make Mike Robinson happy!). Once the dash is back together and installed, the rest of the interior will follow and I want to get the 455HO engine & ST-10 4-speed installed before the winter (ugh...I can't believe I said the 'w' word already!).

Dennis

SD455DJ 08-22-2020 10:08 AM

1 Attachment(s)
We picked up the 'rebuilt' gauges from Bob's Speedometer yesterday for the GT-37 and now it's time to get the 'new' dash reassembled and back in the car. I did not get the gauges restored since I want them to fit the 'patina' of the GT. I'll be on the hunt for some 'better' interior parts, like the replacement dash pad and formula wheel, as we go along.

Notice the odometer reads 09472 miles. Mike Robinson told me the original owner said the speedometer cable broke not long after he bought the car and never got it fixed, so this is the mileage it had in late 1971 when it broke...cool story. Bob's asked if I wanted it 'zero'd-out', but I wanted it left alone to tell the story.

Even though it's a long way off, I'm debating weather to run std. GT-37 issue 14x6 Rally II's or the original 14" Honeycombs that were ordered with the car. I like the idea of changing it up with black steel wheels and dog dishes. More to come...

Dennis

Mister Pontiac 08-23-2020 12:18 AM

Neat story on the odometer. I completely understand not wanting to re-zero to keep the story to tell. I know the comments in the 70-72 section are thin, but even when we don't always say so, great progress, and thanks for keeping us updated! Luv to see others working on their cars and what they're doing. :)

SD455DJ 08-23-2020 12:29 PM

Thanks Todd. I'll continue to post progress (even fairly minor) regardless of any replies/comments...and I do see that folks are looking at this thread. I enjoy sharing what we learn and the problems we encounter along the way.

I really want to focus my efforts on this car now. Years past there seemed to be a new car every year to distract me. The previous caretaker (455HOGT37) wants to see this car done more than me I think!...right Mike? And he has some great stories about driving the GT-37 back from Chanute AFB, in central IL back to his home in southern CA in March of 1988 right after he bought it from the original owner.

Dennis

'ol Pinion head 08-23-2020 01:44 PM

Keep on plugging away @ it Dennis. The broken speedo situation reminds me of a black 71 HO M22 GTO that I owned years ago, the speedo cable casing was partially melted in one spot by its cheesy muffler shop bent header back exhaust.

SD455DJ 08-23-2020 03:32 PM

Quote:

Originally Posted by 'ol Pinion head (Post 6171878)
Keep on plugging away @ it Dennis. The broken speedo situation reminds me of a black 71 HO M22 GTO that I owned years ago, the speedo cable casing was partially melted in one spot by its cheesy muffler shop bent header back exhaust.

Will do Roger. These cars are therapy for me from my regular day job. I've got 5 more years of that before I retire (40 years next May!), so this helps me deal with the stress of the everyday grind and hassles (don't get me wrong, there are many good days too).

Wow, a 455HO/M22 '71 black GTO is a pretty special car. I wish the A/C on this GT-37 was the M22 4-speed instead, but I understand why is was an important option with the original owner living in Del Rio, TX way down south on the Mexican border. It was delivered to Monroe Motor Company at 500 Avenue F (Dealer Code 322 250). Apparently, the OO still lives in Del Rio.

Dennis

'ol Pinion head 08-23-2020 03:38 PM

That's cool. Lot of flyboys drove hot Pontiacs & areas around fighter training bases used to be fertile ground for finding cool Pontiac muscle cars. Laughlin was definitely in that bunch, my dad was stationed out of Laughlin in late '53- mid 55.

SD455DJ 08-23-2020 03:42 PM

Is Laughlin still an active base?

Dennis


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