6x heads

Wondering if anyone may have 6x heads from a 75 or 76 350?  

If you don't absolutely have to have 6X's the earlier 75's had 5C's which are virtually identical.
Steve  
Trying to help... 'cause we don't all have to learn the hard way!

There is 6cc difference in the combustion chamber size but you could mill the heads down to compensate other then that barney is right they are almost identical.
you would have to mill the 5C's 25-28 thousandths to achieve the same size chambers as the 6x 350 heads.  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

The only thing there is, I am wanting to mill the heads 20,000th any way.  If I mill almsot 50,000th, might not fit well with the intake.  

OK why are you wanting to mill the heads .020 more.  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

I was told by a BIG Pontiac man in my area that is what he would do.  Looking for better compression I guess.  I dont question a guy who built his own 8.7 second 69 Grand Prix....I just do what he says    

Ya! a 80CC combustion chamber will give you around 9.2-9.5:1CR any thing over 9.5:1 will be to high for pump gas.  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

Oh also with the 6X heads milling them .020 you are only removing 4CC off the heads.
Which will not bump the compression that much.  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

A better way to get compression is to find some 72cc heads- no. 12,13,16,48,62,670. With the exception of the small valve no.16's, the rest have 2.11/1.77 valves and screw in studs. On a 350 w/ std. bore, any one of those heads will yield 9.1-9.4:1 CR, since sometimes the heads actually measure 75cc.

Geno  

I have a pallet full of heads from65-78 as for 6x a couple sets both 4h and 6h different chamber sizes.everyone thinks 12,13,16,48,62.and 670's are the only heads worth having.not so the 4x and6x can flow better with a little work.If you need closed chamber i have several of those too.I would rather trade than sell.for instance looking for a set of bucket for my 66 i think 65-72 use the same frames and i am going to redue them anyway.What i mean is flow better than ram air heads.there are other codes on the 6x also 2=101cc,4=91cc,6=114cc,7=98cc air,8=98cc standard,9=91cc air  

Ya and the 12,13,big valve 16,48,62, and 670 can flow a lot better with a.little work.  
professional hi-performance engine builder

Horsepower sells engines and torque wins races