Chevy has used 11/32 valve stems for at least 80 years and they use the same grooves so the keepers will work. Rock Auto has the keepers for about $1 each. Chev has used springs that were a little over 2" for the same time frame. The inline springs are just a little bigger in diameter than the V8. So just to be safe I would match the retainer with the springs. I'm not sure that it would make any difference, but it wouldn't hurt to match them. The retainers really don't wear out. Used ones will work just fine.