what's the difference between the heads???
 

hi
I'm going to buy the afr heads 225c 65cc chamber but I'm confused because there are two type of head
1- small bore
2- big bore

I don't know the different between them ? and which one is the better for N/A without turbo/Nos ?

The small bore are for standard 346 cu in engine, large bore is for larger bore engines. If you are buying AFR, just contact Tony and get all the information you need on the heads to make informed decisions on the heads and the options they offer (Upgraded valve springs, milling, etc.)

Ok how can I contact with Tony

can you give me his e-mail please ??

Look under the member's list, he is in there as "Tony Mamo". Shoot him a PM, but note that they are testing right now (according to his response in another thread) so it may be a while before he gets back to you.