In article ,
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I have done some research and heard you can put higher compression flat-top
pistons in the 4.3 and gain a few HP. Who makes these pistons? I have done a
bunch of searches and come up empty handed.

A related question, I have also read that the 4.3 is a 350 minus two
cylinders and that the pistons and rods are the same. Is this true or false?

Almost everything swaps with most 350's. Of course there are 'large jounal'
and 'small journal' 350's, and one can't really make more than a generalized
statement about the 4.3 262 being a 350 minus two jugs. As for flat top
pistons, Geez, everyone makes them for a 4.3, wiseco, TRW, Sealed Power
(who is TRW in disguise anyway) Keith Black Silv-O-Lite. It isn't worth
your time or trouble unless your motor is already apart. If so, go with
forged aluminum. They can take the most abuse, it's all the blower crowd
would ever consider.