[steve25]

Well the rump of the 041 cam and noises of a hot valve train with Rhodes lifters should fill your sonic needs for the car, but with these lifters I would only advance the Cam 2 degrees which takes care of normal timing chain stretch.

Q-jet wise in the least you will still need to run A lighter power piston spring and then with the motor hot confirm that idle mixture screw have good effect when being moved both in and out from a mostly decent idle setting. If the Q-jet you are running is not off a 68 to 70 motor then I do not think you will get a high enough hot idle out of the motor without also having a off idle stumble.

In this case the air bleeds need to be reworked and while kit’s to do this are sold, you might just want to send the Carb out for this work if you’re leery of doing such yourself.

[Formulajones]

There has been a ton of discussion on the subject of install position on the 041 cam around here. Generally most seem to like that camshaft in the 108-109 ICL position. With a 113 LSA that's 4-5 degrees advanced. With a 114 that's 5-6 degrees advanced. Depends on who's cam card you look at.

If it were me in your shoes, I'd take the suggestion of using the 2801 camshaft for your application and have the added benefit of some additional lift over an 068 without the need to increase rocker ratios. It's a very mild camshaft for a 389-400.

I've exploited the 068 for all it's been worth, it's not a big camshaft at all, idles baby smooth, and is an "okay" performer. Not something I'd consider worth while going through all the trouble and expense for just a camshaft swap.

[64Cat_Jake]

Originally Posted by steve25

Well the rump of the 041 cam and noises of a hot valve train with Rhodes lifters should fill your sonic needs for the car, but with these lifters I would only advance the Cam 2 degrees which takes care of normal timing chain stretch.

Q-jet wise in the least you will still need to run A lighter power piston spring and then with the motor hot confirm that idle mixture screw have good effect when being moved both in and out from a mostly decent idle setting. If the Q-jet you are running is not off a 68 to 70 motor then I do not think you will get a high enough hot idle out of the motor without also having a off idle stumble.

In this case the air bleeds need to be reworked and while kit’s to do this are sold, you might just want to send the Carb out for this work if you’re leery of doing such yourself.

Thats some interesting points to consider too. I recently rebuilt the Q Jet that I bought of an old boy here in the UK - the carb turned out to be from a 76 Pontiac 400. It works just lovely! Was out in the garage yesterday in the 25F cold, started as soon as fuel hit the fuel bowls! Was pretty happy with that!

Unfortunately, being in the UK there isnt really anyone I can send it too. (Its not the period correct carb anyway, so it would probably be more cost effective to just buy a new Edelbrock AVS2 or Holley or even EFi) Thankfully I have friends with decent machining equipment so would probably machine it myself.

Originally Posted by Formulajones

There has been a ton of discussion on the subject of install position on the 041 cam around here. Generally most seem to like that camshaft in the 108-109 ICL position. With a 113 LSA that's 4-5 degrees advanced. With a 114 that's 5-6 degrees advanced. Depends on who's cam card you look at.

If it were me in your shoes, I'd take the suggestion of using the 2801 camshaft for your application and have the added benefit of some additional lift over an 068 without the need to increase rocker ratios. It's a very mild camshaft for a 389-400.

I've exploited the 068 for all it's been worth, it's not a big camshaft at all, idles baby smooth, and is an "okay" performer. Not something I'd consider worth while going through all the trouble and expense for just a camshaft swap.

I forgot to mention, as part of the deal, I got some Comp 1.65 rocker arms. Rather than jump in with the two feet, I could stick them on the stock cam in it, measure the performance. Then go to the 068/k2801 with 1.5s, measure. Then with the 1.65s, measure... etc

SCIENCE!

[Formulajones]

Originally Posted by 64Cat_Jake

I forgot to mention, as part of the deal, I got some Comp 1.65 rocker arms. Rather than jump in with the two feet, I could stick them on the stock cam in it, measure the performance. Then go to the 068/k2801 with 1.5s, measure. Then with the 1.65s, measure... etc

SCIENCE!

I like those ideas I love experimenting with stuff to find what works best. If you're on a budget you might find the 1.65 rocker upgrade with the current combo satisfactory. It's certainly easy to do and doesn't take much time.

[242177P]

If you don't have pushrod clearance, those 1.65s probably aren't a good idea.

[64Cat_Jake]

Originally Posted by Formulajones

I like those ideas I love experimenting with stuff to find what works best. If you're on a budget you might find the 1.65 rocker upgrade with the current combo satisfactory. It's certainly easy to do and doesn't take much time.

Yessir! Will report back in the summer!

Off topic, but I watched the vid in your signature - your car sounds ace!

Originally Posted by 242177P

If you don't have pushrod clearance, those 1.65s probably aren't a good idea.

Yeah plus they are mid 60s heads, so the shallower valve angle isnt great for really high lift either.... Got to work with what ya got and measure twice haha

I also got a set of Comp springs and retainers as part of the deal, I they were specc'd for the high lift and I have a feeling that they have a taller seat height too

Lots to think about!

[steve25]

Sorry about the Carb send out recommendation, I forgot where you live.
Do
You know the part number of the springs?

What color strips are on them and are they a single spring with a inner flat wire damper, or duel springs?

[Cliff R]

The 041 is actually just about the perfect cam for a 400 build when used in the correct application. That means RAII or RAIV heads, manual trans, and at least 3.90 gears. It also requires high compression, otherwise the 80 something degrees of overlap KILL idle quality, power right off idle, power in the "normal" driving range, etc.

Rhoads lifters help some with that scenario if you aren't up near 11 to 1 for compression, but IF you really want to see how well the 041 cam works in a 400 build the engine just like the factory did, and set the drivetrain up to effectively use that kind of power.

As far as the carb, moving to an Edelbrock AVS or Holley, or some sort of TB electric unit is just going backwards......IMHO. I've exploited my 1977 Pontiac Q-jet (same as your 1976) for over 3 decades now and NOTHING will outrun it on the dyno or at the track. Plus it gets excellent fuel economy for "normal" driving, instant starts in any weather, and has been dead solid reliable all these years.........FWIW........Cliff

[carcrazy]

Just don't do it!!! Find an 068 cam and you will be much happier!

[1968GTO421]

IMHO I would use the use the Summit 2801, the specs are much like the 068 but give you some more lift (which always improves power) and some lope. You will want to use new valve springs as the old ones are probably "used" up. Lots of advice and opinions here; take your time to sort it all out. Best of luck with your decisions.

(Everyone is basiclly right, the 041 is too much for your current engine and car build, be happy--go smaller.)

[b-man]

Your 1964 ‘345’ heads were among the last Pontiac V8 heads that still oiled the rockers through the rocker studs. Only the big valve ‘716’ 1964 GTO heads (also used on some ‘63-‘64 421 and 389 Tri-Power engines) were oiled through the pushrods like all ‘65 and later heads.

The rocker arms changed in 1967 to a different design, pretty much all aftermarket rockers are the later type and are not compatible with ‘66 and earlier 326, 389 and 421 heads. Pushrod length also changed at the same time, 8.715” early versus 9.145” for ‘67 and later. Most certainly your new pushrods are the later ones, not compatible with 389 heads.

1964 and earlier heads used a 1.53” valve spring installed height compared to 1.586” for most ‘65 and later applications.

So there are a lot of differences that make most of your additional new valve train pieces incompatible.

The best, simplest and most reliable upgrade is to run a factory performance cam like the 068. You can use the new springs you have but the spring pressure will increase a bit due to the shorter installed height. The valve train geometry will remain as the factory produced it with the 068 cam so no headaches.

Keep in mind that the factory press-in rocker studs aren’t all that reliable when you add the additional stress of stiff springs and higher lifts, you’d best forget about running 1.65 rockers with them even if the pushrods didn’t need clearance added (they certainly would). The studs liked to back out of the heads even in pure stock applications, oversized studs were stocked by dealers to fix this issue back in the day.

Good luck with your project.

[steve25]

B-man stuffed it all in one post for you Jake!

[64Cat_Jake]

Originally Posted by b-man

Your 1964 ‘345’ heads were among the last Pontiac V8 heads that still oiled the rockers through the rocker studs. Only the big valve ‘716’ 1964 GTO heads (also used on some ‘63-‘64 421 and 389 Tri-Power engines) were oiled through the pushrods like all ‘65 and later heads.

The rocker arms changed in 1967 to a different design, pretty much all aftermarket rockers are the later type and are not compatible with ‘66 and earlier 326, 389 and 421 heads. Pushrod length also changed at the same time, 8.715” early versus 9.145” for ‘67 and later. Most certainly your new pushrods are the later ones, not compatible with 389 heads.

1964 and earlier heads used a 1.53” valve spring installed height compared to 1.586” for most ‘65 and later applications.

So there are a lot of differences that make most of your additional new valve train pieces incompatible.

The best, simplest and most reliable upgrade is to run a factory performance cam like the 068. You can use the new springs you have but the spring pressure will increase a bit due to the shorter installed height. The valve train geometry will remain as the factory produced it with the 068 cam so no headaches.

Keep in mind that the factory press-in rocker studs aren’t all that reliable when you add the additional stress of stiff springs and higher lifts, you’d best forget about running 1.65 rockers with them even if the pushrods didn’t need clearance added (they certainly would). The studs liked to back out of the heads even in pure stock applications, oversized studs were stocked by dealers to fix this issue back in the day.

Good luck with your project.

Thanks so much for this long and informative post B-Man!

The curse of 1964 strikes again! Seemingly every time I look for a part or cross compatibility, the curse strikes

Sure enough, I just measured my shiny new pushrods - 9.145"

My new rocker arms are Comp 1452-16, so I'm guessing they are no good

steve25 - The springs are Comp 955-16s

They are a dual spring, so seat pressure could be reduced by not running the inner spring I suppose

Funnily enough, I was just reading through B-Mans excellent write-up on Early Vs Late heads (http://forums.maxperformanceinc.com/...d.php?t=636024) I was starting to get a bad feeling and this confirms it haha


I'm guessing all these issues would go away if bought a set of 65+ heads, I know a guy that might have a nice set of 70 HO heads still

[steve25]

Man, you just keep striking out with things I am dam sorry to say!

1970 HO heads would have a 87 CC chamber since they where used on a 455, this would give your 389 only some 8.5 compression.

Next those 955 spring are for race only with big time pressure.

Those rockers would work if you yanked the heads off and had screw in studs installed and ran hollow push rods like you have, but of the needed length,

[4zpeed]

....

Glad to see you've reconsidered, best of luck!



Frank

[64Cat_Jake]

Originally Posted by steve25

Man, you just keep striking out with things I am dam sorry to say!

1970 HO heads would have a 87 CC chamber since they where used on a 455, this would give your 389 only some 8.5 compression.

Next those 955 spring are for race only with big time pressure.

Those rockers would work if you yanked the heads off and had screw in studs installed and ran hollow push rods like you have, but of the needed length,

Haha just my luck! Well not to worry, its only money

In good news, I got a lead on some 1969 62 Heads, apparently from a GTO - Looks like they have a 73cc camber, so only dropping 5cc's. I ran it through a compression calculator and it looks like it drops the compression by about 0.625 or a point. Even the best premium fuels we can get over here are basically 93 octane in the US - So dropping the compression a little bit can't hurt

I do wonder, if the pushrods in the 1964 motors are solid, does that change the lifter design too? I'm guessing if the lifters cant bleed down through the push rod centers, it'll hold the pressure in too?

I have a set of Comp 852-16 Lifters - let me guess, no good?

[b-man]

The 1964 pushrods are hollow to oil the pivot points. The early rockers lack the oil spurt hole at the pushrod cup to splash oil the rocker balls.

With the #62 heads your new pushrods, rockers and everything else will now be compatible.

However now you will need a ‘65 or later intake to match the new heads.

[64Cat_Jake]

Originally Posted by b-man

The 1964 pushrods are hollow to oil the pivot points.

With the #62 heads your new pushrods, rockers and everything else will now be compatible.

Ah gotcha, makes sense!

Well, sounds like the #62s might be worth pursing then! Luckily I also have a 65-88 OE QJet intake knocking around too. Am I right in thinking that the HVAC heater hose comes off the back of the passenger side head, rather than the water cross over at the front?

[b-man]

Originally Posted by 64Cat_Jake

Ah gotcha, makes sense!

Well, sounds like the #62s might be worth pursing then! Luckily I also have a 65-88 OE QJet intake knocking around too. Am I right in thinking that the HVAC heater hose comes off the back of the passenger side head, rather than the water cross over at the front?

Yes new heater hose location.

Another fly in the ointment: the later heads have different valve locations so they don’t match up with the valve reliefs in the pistons. You’re best off running a low lift 068 factory cam to prevent interference.

[64Cat_Jake]

Originally Posted by b-man

Another fly in the ointment: the later heads have different valve locations so they don’t match up with the valve reliefs in the pistons

Of course

Oh well, back to the drawing board!