optimum ring and pinion ratio for 33" tires L43 4 speed

Started by HACKJOB, March 29, 2005, 04:27:50 AM

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HACKJOB

My on going project truck is a 79 Toy long bed, Equipped with a 20r and a L43 tranny.  This summer when I escape from New jersey back to good ol So Cal im planning on installing a Marlin Transfer case, 33 inch tires and 488:1 R&P  my question is is there anyone out there that uses this combination and how is it On the highway?  What will the rpms be at 70mph, is it drive able or will the rpm be too exessive for freeway driving.  My plan is to drive this vehicle to places like the Black rock desert, Moab and Colorado originating from Oceanside Ca. while expecting decent performance , economy, and driveability on road and excellent performance off road (Marlin Transfer)  any input would be greatly appreciated thanks.

kyle_22r

having had the L43 in my truck myself, i can relate to this problem.  it presents kind of a paradox.  optimally for a 4 speed with 33" tires you'd probably want 4.56 gears to keep the revs down on the freeway.  this wouldn't be a problem with a later 4 or 5 speed tranny, since they have a 3.93 first gear.  however, the L43 has a 3.67 1st gear which makes getting started with higher gears a real chore.  to match a later tranny for starting out, you'd want 5.29s, but you'd want 4.56s for cruising the highway(if that makes any sense).

if you want to stay with the L43, i'd pick 4.88 or 5.29 gears if you mostly drive in town, or 4.56 or 4.88 gears if you drive a lot on the highway.  fortunately on the highway with 4.88s you'll be turning at a lower RPM than you would with stock tires and the stock 4.38 gears. just my :twocents:

brainlessfool

A good day working, that's just sick :reg: