How fast an engine rev's also comes into play.. My hemi could throw or break a belt in one hit. Changed to a top cog belt that actually slips a little on hit and hasn't popped off in 8 years. Chevy 302's did the same thing because of how fast they rpm. Probably the reason you couldn't get ac on the cars because you couldn't get the long belt to stay on.

Last edited by second 70; 03/12/19 11:52 AM.