[andysam]

I dont want to change out the pistions or crank, but what is the biggest cam i can put in? I have a 1968 289, or 302 not sure, but it is a 'c8'so i have heard good things about this block, and also has the made in mexico on it with a stamped '302' on it.i have ported the heads (which have '289' on them). Now if I want to put bigger valves in my heads, say 2.02 and 1.60, what is the biggest cam? thanks

 

[mustangzrule]

The stock heads won't support 2.02/1.60 you can go max of 2.02/1.54 with hardened seats. Considerable money for stock choker heads. As for cam size, I easily ran the Summit cheapo 224 degree cam and had tons of PTV clearance. If I remember, the pistons are basically flats? It was a few years ago. If the pistons have dishes, you are golden to the limit of your springs.

 

[andysam]

do you remember the part # for your cam? And what was the lift on it?

 

[1965FALCON]

You should be safe with anything up to 0.50 lift, any more than that and I'd check the clearance with clay (not a bad idea to do it regardless since you have the heads off).

As for valve size I wouldn't go any more than 194/160. Those heads are not going to flow any better with anything bigger unless you are doing some radical porting.

Make sure you think about the whole package, balance your cam, head flow, intake, exhaust to all work in the same rpm/flow range.