Casting #s For Good BBC Heads
 

I plan on "waking up" my stock 1972 402 BBC. I want to run something that will raise the compression and breath better than the stock truck heads. I would like to run a Comp Cams 270H, performer manifold, built quadrajet and some headers. Nothing crazy just a hot street engine.

I have a list of BBC head casting numbers. Maybe you guys could suggest some good performing affordable heads up to hipo Chevelle or Corvette heads. Whats good and what to steer away from. I hear my stock 402 truck heads basically suck.

Can I use square or oval port on my 402?

Should I use closed chamber or open?

Thanks for any help.

Re: Casting #s For Good BBC Heads
 

The best oval port heads are 049,781 or 820 but that does not mean they are that good as they all can be improved with porting and bigger valves.Unless your going for big HP numbers you dont need rect.port heads as they will kill some bottom end and a 402 is at the small end of the BBC world. Chamber CC run anywhere from 122cc down to 110cc so you can build compression pretty well within that range with the right pistons. Stay away from peanut port heads - they are oval port heads but just dont flow well at all and run out of flow at anything above 4K rpm.Torque motors are all they are made for. You say the stock heads on your 402 are junk,well you need to look at the numbers to see what you have as they may be better than you think - a little pocket porting and bigger valves and they may be just what you need. Remember this before you sink alot of $ into re-doing heads,for just a little more money you can get a set of iron merlins which will out breath any older head even after all the work is done. Check out mortec head # listings and it should give you a good idea whats out there.::::::CB

Re: Casting #s For Good BBC Heads
 

:agree: Also look for some 215's. They are thte large oval port,closed chamber heads. But with closed chamber heads, you have to run a closed chamber piston.
-Lance

Re: Casting #s For Good BBC Heads
 

If your engine is stock, you may have closed chamber 100cc heads, so most newer heads will lower your CR. I agree with the above statement to check your casting #'s. Not all of the early pickup BBC stuff had peanut ports. If you have large ovals and go with bigger valves and a 3-angle that should help.

Re: Casting #s For Good BBC Heads
 

I wouls stay away from the factory aluminum heads Ive seen vavle seats pounded out and into the heads with stiff springs.

Re: Casting #s For Good BBC Heads
 

I will pop off my valve covers and check my #s before I buy anything.

Thanks for the input!

Re: Casting #s For Good BBC Heads
 

I don't think they used closed chambers on the truck motors. But definately look at you casting numbers, then decide what to do!!

Re: Casting #s For Good BBC Heads
 

So with open chamber heads to raise the compression I would need a domed type piston? And with a closed chamber head I would need to stick with a flat top piston?

Are my stock 402 pistons most likely flat tops?

Re: Casting #s For Good BBC Heads
 

No they are domed pistons from the factory. The dome is shaped kinda like the combustion chamber. Just look for a set of closed chamber heads if you want to bump up the compression and change valve size if needed. The 270H cam runs real well in a 396/402 so I think you made a good choice for a cam.

Re: Casting #s For Good BBC Heads
 

Thanks!

There is a big physical difference in an open and closed chamber BB head. Would the pistons have to be changed too so the dome would not contact the head?

Sorry, just never had one of these apart before.