Originally Posted by MikeN
The 1277 bearings are available from Summit https://www.summitracing.com/parts/cle-ms1277hg as well as the 527 https://www.summitracing.com/parts/cle-cb527hnd .

I have been running the MS-1277HG main bearings in my race motors for years.
But I don't see any -10 under on Summit's site right now. My new motor is standard size (new Callies crank), so it is not an issue for this build.

1993 Daytona, 5.50 at 130mph (1/8) 1.19 sixty ft (PG). Link to 572 B1 - Part 1