the way I understand it, it's an 848 head (last three digits of the casting number) which is a 235 head. You don't need it for the full flow system. The only advantage to it is that it's a slightly smaller combustion chamber, therefore, it will give you about a half point higher compression. You will have to drill the steam holes in it to fit the 261 properly. Would you mind telling me what the casting number is on the block? I actually want the block you have, and you want the block I have! I have the full flow 261, factory (1961). I want the one you have. If you'd be willing to trade, I'll cover the cost of shipping for both of us.
805-231-1645
Josh
