Yeah it turns out that 70+ rings were 5/64 and 66-70 rings were 1/16" in 250s (but apparently 230s were still 5/64).

So anyway, apparently I'll still be able to use those 5/64 rings on that one replacement piston I bought but now I need to decide what do to with the other pistons' rings. My options are
1) Reuse the 23,000 mile rings that are already on there
2) Buy the only set of 1/16 I can find on ebay but they're Moly rings instead of the original cast iron that's going on the replacement piston.

It seems smarter to just reuse the original pistons and just hone that one cylinder for the new rings on the replacement piston to seat correctly.


69 Buick Special Deluxe. Intercooled Turbo Chevy 250 @ 15psi on a stock long block. It's kinda fast.