Wow .008 with a cast piston.
I just had to hone a block to .003 over recommended bore finish size for cast pistons.
Customer wanted it to stay with a .040 overbore but it had locked up at some point and there was aluminum transfered on the cylinders and a bunch of surface rust. ( Car 351 Windsor...
I'm surprised that piston manufacturers haven't had an "in between" alloy developed yet, with the great qualities from both 2618 & 4032.
I had to have my 4032 pistons coated from line2line coatings and run .0015 p/w clearance with gas ported total seal top rings.
The previous machinist didn't...
No, we just raised the pressure on the regulator.
It was at 3 and went up to 5.5
I say we, he did but I mentioned checking fuel pressure.
Float level was great, just not filling fast enough down the track