[b-man]

A factory performance cam is the best choice if you’re not into shelling out for a bunch of non-stock valvetrain components.

The tried-and-true 068 is a decent performer that won’t require anything other than a good set of stock replacement valve springs. Straight 7/16” studs and poly locks are a wise upgrade that also allow you to convert to an adjustable valvetrain but not absolutely necessary. Stock converter works fine with the 068, as well as stock log exhaust manifolds.

Once you start stepping up the cam past factory issue grinds there’s a number of pretty much mandatory upgrades required for the engine, drivetrain and exhaust if you want to end up with a well-balanced performance car.

Bottom line - to stay on a budget you’re best off sticking with a factory performance cam, Pontiac is one of the few brands that offered a decent selection of performance cams. Your stock rockers and pushrods will work fine, just inspect everything for wear or damaged and buy inexpensive new replacements if they don’t pass muster.

[tom s]

I used a 068 and lifters and springs from Paul Spotts in my 63 421 HO engine.Was very EZ and inexpensive.Cant go wrong.Tom

[96SS]

Thanks for the feedback, I don't mind going with a little hotter cam. No problem with buying springs, and rockers. Looking to get input on a general consensus for what is needed to let say run the Voodoo 3 cam. The TA has headers, 3.42 gears, the weight should be about 3750 with me in it.

Mike

[Jay S]

You can run any of these cams mentioned in this thread with the 68404 springs and stock push rods. They need 7/16” studs with the bigger cams. The Lunati springs that come in the kits are for a little taller installed height than stock. Crowers are a easy fit.

That much converter you might as well run the 703 voodoo or that lunati 712.

At least do the summit 2802. It wouldn’t bother me to much to run the stock studs on it and the 68404s with 1.5s. The 7/16 studs would better, but I doubt you would have an issue.

[96SS]

Thanks Guys, so here is what I think might be a good combo for this application of 400 bored .010 over, stock #13 heads (est. compression of 10.25), headers, 3.42 gears.

Combo 1: Summit 2802, or RA 68 with Crower 68404 springs, 7/16 studs, with stock stall, and factory intake
Combo 2: Voodoo 3 or 4, RPM intake, 7/16 studs, headers and 3.42's, with 3200 stall
Rockers? make and model
Lifters? make and model
Springs? make and model
Do I need new valves? Thought these would work:
5000 Series Ferrea Stainless Steel Valves
Intake Part# F5143
Head Diameter: 2.110
Steam Diameter: 11/32"
Overall Length: 5.095
Tip Length: .250
9 Deg Flo-Dish Head 30 Deg Seat
Exhaust Part# F5144
Head Diameter: 1.770
Steam Diameter: 11/32
Overall Length: 5.110
Tip Length: .250
9 Deg Flo-Dish

I have numerous, carbs of makes and models to fit any of the above applications

Thanks for everyone's input on this. I am hoping to get away with under $1000 for the valve train parts if I run combo 2 and not have to perform any head machine work.

Mike

[tom s]

JMO,at 10.25 CR your going to be buying race gas.Tom

[96SS]

Tom, what do think I should try to lower the CR to? I was only using the 10.25 CR based upon the factory rating for this engine.

Mike

[b-man]

Your #13 heads are unique. They have the largest combustion chambers of all of the ‘67-‘70 high compression 400 heads. Most are in the 78 to 82cc range, not the 72ccs advertised.

I’d say you’re in the 9.25 to 9.5:1 range in actuality. Forget about the 10.25:1 advertised compression ratio, it’s not an accurate representation.

I don’t see the need for race gas nor octane boosters, just use the best 91 to 93 octane gas (no ethanol if possible) that you can find.

[tom s]

KNOW what your finished CR is!IMO 9.5 is safe with 91 gas,better with 93.Many disagree and like to push it,I dont.Tom

[phil400]

I've read on this forum many times that you should install hardened exhaust seats in the older heads. Haven't seen it mentioned here, not sure if you were planning on that.

[Jay S]

That is a good point Phil. To me that depends on what the expected life of the engine is and it’s future use. The heads are not going on a fresh engine. But it sounded like this engine wasn’t sporting a lot of miles. It should be able to take a valve job with new valves and run it. New valve guides and seat inserts would likely double the cost. Add an fuel additive if seat wear is a concern. Have the shop leave the exhaust seat wide, narrow exh seat won’t last long on a non induction hardened valve seat.

FWIW....new valves and a valve job, 68404 Crower springs, cut the guides for posi seals, run the stock retainers, 7/16 studs, stock rockers and one of the hft cams that has been picked with Hy-Johnson’s. Don’t worry about the installing seats unless the heads already have a sunken valve.