Block is .001" over 83mm, should i bore?
 

My machine shop says i'm 0.00048"(3.2682) over 83m(3.26772) and i have a few small blemishes on two cylinders. He seems to think it will be 'fine' but its up to me.

I'm aiming for 300whp and was originally looking at Wiseco Forged (83.5mm, 8.5:1) but that would require a bore.

I found a forged 83mm piston but they are actually more expensive than the 83.5 pistons. https://www.vividracing.com/wossner-...-p-132283.html

So i guess the question is, should i spend the extra money for a 83mm piston or just bore it out to 83.5m?
He's already honed it due to a miscommunication on my part.

The 2618 piston material does have a high expansion rate and usually requires more clearance than what is built into the piston. It might be alright to just hone it out enough to clean it up. I personally would bore it which would allow you to have round and straight cylinders with the desired clearance.

If it was my block, I'd source x4 alloy 4032 pistons sized 83.5, mark them #1, #2, #3, #4, and have the block shop bore each cylinder on the closer side of the manufacturer's piston-to-wall clearance for each individual cylinder.

Be warned, don't use supertech rings with supertech pistons. The supertech rings have low tension and cause excess oil consumption. Supertech 83.5 pistons with Wiseco 83.5 rings are a popular combination around here because of that.

All of the aftermarket piston manufactures (Wiseco, JE, CP and SuperTech/Malhe use the same ring pack. The low tension oil ring info was never correct and there is no other option.