[SD455DJ]

Greg, Forgot to say that the #11 head is also on all the 350 2-bbl motors and is very common...can't believe I forgot to include that in my previous post. After a clean-up cut on the deck surface you'll have close to a true 9.0:1 compression 400 and that along with a Summit 2801 cam will get you your 325 hp with RA exhaust manifolds, 68-71 4-bbl intake, and a well tuned Q-jet and recurved distributor. If you go the large valve conversion, you'll be closer to 350 hp. Good luck!

Dennis

[PONTIAC LARRY]

68 350 #17 heads are nice on a 400 too 9.0-9.5:1

[SD455DJ]

Originally Posted by PONTIAC LARRY

68 350 #17 heads are nice on a 400 too 9.0-9.5:1

PONTIAC LARRY, Yes, I forgot to mention the '68 #17 350 small valve head as another good candidate to raise compression moderately on a 400 engine.
So the '68 #17, '69 #46, '70 #11 & #15 are the heads to get. I would even run the small valves, pin the stock rocker studs, and install good valve springs that accept up to .500" lift.

Dennis

[footjoy]

I picked up a set of 1970 #15 heads today. I guess we will see what it does.

[SD455DJ]

Greg, That was fast. All these heads cc in the 85 - 90 range before cutting, so with a .010 clean-up cut, you'll be in the 'zone' of high 8's/low 9's depending on other factors such as piston deck height and head gasket thickness. I'd go with a .040" crushed thickness gasket.

Dennis

[footjoy]

Since I came from the chevy camp and most people put hardened seats in.When I have talked to people mostly people trying to sell me heads say hardened seats aren't necessary with Pontiac heads. What is the consensus on that in Pontiac Land

Thanks

Greg

[b-man]

Put hardened seats in.

The exhaust valves can recede on Pontiac heads.

I've seen the exhaust valves recede by 1/8" to 1/4" on two different sets of Pontiac heads, 1969 #48 400 and 1971 #66 455 heads.

The #48 heads only needed about 15K miles to heavily recede, the #66 heads did the same in 30K miles.

Honestly I can't see putting all that money into rebuilding iron heads and stopping short by not installing hardened seats for the exhaust valves.

[footjoy]

Originally Posted by SD455DJ

Greg, That was fast. All these heads cc in the 85 - 90 range before cutting, so with a .010 clean-up cut, you'll be in the 'zone' of high 8's/low 9's depending on other factors such as piston deck height and head gasket thickness. I'd go with a .040" crushed thickness gasket.

Dennis

Ok at this point which will give more bang for buck a camshaft or going to 2.11 valves, or just stay with stock cam and 1.96 valves. Remember it is a cruiser that occasionally take off fast.

Thanks
Greg

[SD455DJ]

Greg, I may get some opposing viewpoints, but I would leave the heads alone, except for new 1-pc valves, new springs, and either pin the existing pressed-rocker studs, or have screw-in studs installed...then go with a 2802 Summit cam & lifters. Make sure to have your heads cut to give you an 85 cc chamber volume and depending what your deck height is, choose a head gasket to give you .045" quench +/-.005". If your pistons are in the hole .015" or more, I'd get the thinnest head gasket I know...the .027" Commetics, to get you in that quench range. If your deck height is less than that, you can run a thicker gasket to get you close to the desired .040" min. quench.

I'd run the RA manifolds with the 2802 cam and if you keep the std. manifolds, maybe back down to the 2801 cam.

Dennis

[footjoy]

How do you ID a cam. Is there a number somewhere on it? The motor was rebuilt by others and I don't have access to that info.

Thanks

Greg

[SD455DJ]

Greg,

Typically, on aftermarket cams there is a number scribed/stamped into the face of the rear cam journal...meaning you can't see it unless the cam is removed. Factory cams have a letter code stamped on the snout of the cam, so easy to determine.

If there is nothing, you have to degree it to determine the duration and lift to know what you have.

Dennis

[Squidward]

I think the 2.56 gears are too much to do a 2802 cam. 2801 specs would be better, especially considering OP's stated intentions.

[SD455DJ]

Originally Posted by Squidward

I think the 2.56 gears are too much to do a 2802 cam. 2801 specs would be better, especially considering OP's stated intentions.

Good point Squidward! The 2802 will give your 400 a little lope while the 2801 will be fairly docile. Oh, and as B-Man recommends, install hardened exhaust seats regardless of the valve size.

Dennis

[footjoy]

Does the 2801 need to be degreed?

[SD455DJ]

Greg, All new cams need to be degreed to be installed correctly. There are many threads covering how to do this and youtube videos as well.

Dennis

[SD455DJ]

Greg, Responded to your pm, btw. Dennis

[footjoy]

I am looking for some Ferrera 1.96 valves I have not located any. Where can I buy some.

Thanks Greg

[footjoy]

OK got the #15 heads to the head shop should be about 2 weeks to get them back.

Thanks for all of the help

[SD455DJ]

Greg, What are you having done to the heads? Dennis

[footjoy]

Originally Posted by SD455DJ

Greg, What are you having done to the heads? Dennis

I am having them magnafluxed, CC'd and then if all is well I am having hardened seats put in the exhaust side, threaded studs put in and a valve job.
I gave him cam card for a K2801 cam and he is going to put springs in if needed.

Greg