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06-17-2010 04:07 PM #1
454 3spd w/4.68 gear rpm on highway...
I figure you hotrod guys know your motors, so I have a quick question...
I have a 78 GM Chassis motorhome with a 454 w/4barrel carb and 3spd auto trans (turbo400 i think) with 4.68 gears (dana 11?).
At normal throttle, it will shift into 3rd at about 25mph. 60mph is a long way away from 25mph and i'm all out of gears! At 60mph it is rev'ing about 3200rpm.
I've been contemplating throwing a set of 4.10 or even 3.73 gears to improve mileage, but I'm curious as to if it is even worth it?
Is 3200+rpm ok for these old 454's? I have a 12hour drive planned in a few weeks, and I know 3200rpm is ok for a little 4cylinder, but a big 454 seems a bit high.
Thanks for the advice!
You're welcome Mike, glad it worked out for you. Roger, it's taken a few years but my inventory of excess parts has shrunk a fair bit from 1 1/2 garage stalls to about an eight by eight space. ...
1968 Plymouth Valiant 1st Gen HEMI