I am going to buy a 350 and swap it in place of my 305, and the seller has two different pairs of heads available. He has iron L98 heads, or 881 castings. I looked at mortec.com, and found that the 881s have 76cc chambers and 2.02/1.6 valves. The L98s have 58cc chambers, i THINK. Which are superior? I like compression, and i think that because this is a truck block it will have dished pistons. Is the extra flow generated by big valves worth the hit in compression? Thank you.
Matt

 

The iron L98 heads are actually 64cc, not 58.

Anyway, I'd use the L98's if you are stuck with dished pistons. The valves arent worth it IMO.

 

The Iron head L98's are 64cc's and will give you as much performance as the 2.02/1.60 881's because of the compression loss. Especially if you will do a mild port and polish job on them before installing them. If you do port and polish concentrate on the short side radius under the valves to allow more flow and I debur the intake side and port match leaving intake side runners with semi rough finish with flap wheel. Exhaust side open up and I polish in steps with rock then #60 and #80 cone sand then once smooth start with a king size rubber eraser wheel and bring to a mirror finish. There is a detailed descript on here with pictures if you'll call it up on a search. Hope this will help.

 

I stand corrected about the chamber size. I am planning on doing a port and polish on them i think, especially because they are allready off the motor. Thank you very much for all your help.
Matt