I had diamond pistons never had a problem with them.
Ran constant 2.6" pulley on em but i also watched A/F like a hawk3
I had it all done to my block will i do it again. NO
The end of my car ended up being a snapped crank.
I had a bored .20 over, balanced crank, diamond pistons, double roller, Head work that matched Intense S3 hears and then some, over sized valves, IS3 cam, Clevite 77 Bearings, and total seal rings.
IF your not gonna go all out, i would keep block stock, just replace bearings and seals, and TC tensioner.
Before i went all out i had basics, 3.25, tog headers, 1.9 rockers later upgraded to a VS cam, intake, exhause and PCM. When i threw the vs cam in i dropped to a 3.0 dailey and a 2.9" fun at that time i had 2-3kr w/ 2.9"
After i talked to many other people at the time stated our cranks are better left alone.
at the time i was making damn near 400whp and just hit 500wtq.
I also hear from some of the old top togs that had to pave the road for us, Chris green, ed, at the time stated stock blocks is what they ran doing 300+whp. Just watch kr // Af and it will hold out. I been out the game for so long i dont know to do anymore.