Are there any specific break in procedures for a 1954 GMC straight 6? Rebuild kit was from Kanter. I assume steel rings and aluminum pistons but I'm not sure. It's an Ebay hand me down.
I have receipts from Kantor and the machine shop so I know this motor was professionally rebuit.
I have seen various break in suggestions on Stovebolt as follows:
Run at 2000 RPM for 10-20 minutes with John Deere "run in oil". Others say that this is a mistake as your rings will never seat.
or run 20W non-detergent for 500 miles then switch to 30W detergent.
or Rev up to 40 then back off to 20 a few times to get the rings to seat. This must be done within the first 20 miles. (question here is what gear to use, 3rd may not go to 40 and 20 in 4th would be lugging)
or drive about 700 mile at varying RPM's without lugging or hard acceleration using. (should this be with detergent or non-detergent?)
I've put about 12 miles on this motor using the last technique and want to be sure I'm doing it right. I haven't noticed any smoke as some posters describe during break-in.
