Running a WS6 T.A. LS1 with 4L60E
in 53 Chev Panel half ton.
Mustang 2 IFS and 10bolt 8.5,
3:73's in rear. Plan on a 8 by 16"
wheel with P245/55. Thats about
26.6" tall.
Question: anyone know expected rpm's
in O.D. at speed?
Would 3:42's be better?
Cheers
Your current combination of 3.73 and 26.6 inch tire diameter yields 2825 rpm at 60 mph in a non-overdrive tarnny, but only 0.70 x 2825 = 1978 in overdive with the 4L60E.
That's actually pretty good. If anything, I would go STIFFER on the final gearing, to get to maybe just under 2200 rpm (that would be a 4.11 axle for example, which would yield 2180 rpm).
I base that one two factors:
1. The LS series of engines are not torquers, but rather high rpm engines. If you are under 2000 to 2200 rpm at 60 mph, your vehicle will downshift a lot on uphills, and will never "feel" as strong as its peak power numbers suggest.
2. These are VERY durable engines that can run high rpm for a long timee without any trouble. I have been running my 5.3 liter LM4 engine (the 5.3 all aluminum version of the LS1), with a Corvette Z06 cam, dual exhaust and supercharger at just under 2200 rpm at 60 mph for the past 23,000 miles. It loves it, and the fuel mileage is wonderful (over 20 mpg at 60 mph even with 575 crank horsepower on tap.
Jim G
