djontz

Hello all. First post here, and I'm pretty new to Oldsmobile stuff as well. My son has a 1984 Toronado that bit the dust a little while back; he wiped out the crank bearings by not getting the oil filter on tight enough. We're looking to do a modest/budget rebuild but the block is definitely going to have to be bored and honed as it has a decent ridge at the top of the cylinder. I'm done some searching, but I'm having trouble locating .030 or .040 over pistons for this motor. Does anyone actually make them anymore?

Thanks in advance for your time, I do appreciate it.

joe_padavano

I got bunches with a thirty second search on Google. Cast and hypereutectic, in 0.020, 0.030, 0.040, and 0.060 over. Not clear how thick the walls are on a lightweight 307 block, however.

https://www.summitracing.com/search/...type%3Apistons

djontz

Huh. Guess I just suck at the searching thing. Thanks!

Jeff Stout

Im .020 overbore now and see no problems. Im surprised on cylinder wall wear.They are fairly hard surface. More then normal front what Ive tested.

83hurstguy

My 307 was at 0.040" without issues in the past. Never knew it until I took it apart and saw the 0.040" pistons.