The official FABO machinist/member collaboration, busted 340 thread

I will say this though. There've been MILLIONS of those old heavy *** TRW pistons used through the years and they ran fine.

Exactly. I am building a 440 with the old TRW six pack pistons and rods.

Others talk about how heavy they are, and they are technically correct about the weight.

But does it really matter in an RV engine that won't spin north of 4500 rpm?

As long as you have a good set of rod bolts I say no.

Bottom line, for a 340 street engine if I had a set of the TRW forged heavy pistons would I use them? Sure. If I had to buy new pistons though the lighter ones (provided a rebalance is in the budget) are a no brainer.