Intake manifold question

Would a 1967 400 intake fit a 1975 400?
Thanks  

Yes, but you must use the 1965-71 intake gasket with a sheet stainless steel block off plate to cover the exhaust crossover mismatch.  If exhaust crossover heat is not a concern then leave it blocked.  If you want heat, then you'll have to make a hole matching the 1975 head (smaller than intake opening).  The block off plate goes between the head and the gasket, not gasket and intake and should be about 0.015" thick.

Otherwise, the intake bolts right on.  

Thanks for the reply. I don't want the crossover heat. I'm building this engine for a dirt track car and the rules rquire a 2bbl manifold, which is proving difficult to find. But I have a lead on one off a 67. Also excuse the user name change, I couldn't log on with the old one for some reason.  

Painless, not sure where you are based, but I have a pair of 2bbl intakes: a 75 and a 76. You are welcome to either one if it works for you. Using a Pontiac is a different approach, most guys shy away from them due to the weight compared to the typical SBC. I've been involved in dirt track racing and just finished three years as crew chief on a street stock car. Check my pages on Reader's Rides under Grand Prix. Send me a PM if there's anything I can help you with.
Steve  
Trying to help... 'cause we don't all have to learn the hard way!

There is one problem with the 2bbl manifold compared to the QJet.  While the latter flows about as well as many of the aftermarket dual plane aluminum ones, the 2bbl has much more "squared off" runners and would not flow as well even if it had a QJet flange on it.  

Unfortunately, many dirt track sanctioning bodies require factory 2bbl manifolds as a means of restricting rpm and hp in an attempt to keep costs down in the lower classes. Some allow a 4bbl manifold with an adapter to a 2bbl, but most allow only the 2bbl manifold and adapter to a Holley 2300 series 500cfm 2bbl. It doesn't stop the real hardcore racers from spending huge money on their motors. I've seen 12.5:1 355/358 SBC's with the ultralight flattop pistons at "0" deck height and the old 327 "fuellie" heads angle milled almost to the water jackets, 2.02" and 1.60" lightweight valves and huge solid lifter cams, 1.6:1 stamped rockers (to pass the "tech" inspection at midnight in the dark pits!). These guys routinely spin these little monsters well over 7 grand, I've personally seen the recall on a friends tach at 7600, and all this for a chance to win $100 for first place! I can't imagine trying to do the same with a Pontiac, torque is great but traction (or the lack of it on dirt) is the enemy.
Steve  
Trying to help... 'cause we don't all have to learn the hard way!

I'm inclined to go wth an older manifold due to the lack of EGR crap. If this 67 2bbl deal falls through I'll contact you about the 75-76 manifold.
I'm buiding a hobby stock just to get my feet wet first. At my local track the street stock class has turned into a money/engine war. I have heard of guys spendng 15k on their engine and yes they rev to the moon.
One other part I need and can't seem to find is the motor mounts that go on the cross member. A previous owner hacked them to move the engine forward after swapping in a th400 for a th350 instead of shortening the drive shaft, go figure.  

Instead of trying to find original mounts, make a set of solids. If you have the block brackets, get a couple of pieces of C channel that fits inside the brackets, drill the hole for the thru bolt and set the motor down on the crossmember. Move it as far back as you can get away with- it'll handle better, square it up side to side and weld the mounts to the frame.
Steve  
Trying to help... 'cause we don't all have to learn the hard way!

I will proably end up fabricating something myself. The rules say the number one spark plug can't be behind the ball joint I think it was pretty close already, the engine is out of the car right now. Oh and it is a 73 Firebird.