I have a 2,800 stall convertor for my built-998 trans /401(INDY heads..etc) setup that's going in my 72 Gremlin.I've been calculating rpm @ 55 mph. Dumb question... should you have the rear ratio so that the convertor is locked at highway speed?? I have a HUGE remote mounted trans cooler with a electric fan on it. With my tire size a 4.11 (have already)will run the rpm slightly higher @55mph than it locks at..BUT i also have a fresh 3.70 i can use. With the 3.70 ratio i won't quite be locked up @55mph. Just wish there was a formula for dummies like me!! I've always had 4 speeds before!! Thanks to anyone with helpful info. Joe Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/BaadAssGremlins/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/BaadAssGremlins/join (Yahoo! ID required) <*> To change settings via email: mailto:BaadAssGremlins-digest@xxxxxxxxxxxxxxx mailto:BaadAssGremlins-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: BaadAssGremlins-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/