89 4 speed questions
 

Just got a 89 k2500 4x4 with 6 lugs ??? It has a low geared 4 speed stick It shows L, 1, 2, 3, R, on the shift knob. It sounds like at 60 mph the motor is pushing like 3000 or 4000 rpm in the highest gear is this normal ?? I mean what is the "top safe" speed of this I dont want to blow anything up. If anyone has any info on this transmission any info would be great. Truck is in A++ Shape. New 350 new clutch

Thnaks, :chevy:

Re: 89 4 speed questions
 

Its an SM465 and its final ratio is 1:1 just like any other non overdrive trans, or like 3rd gear in a 700r4/4L60/4L80 auto. Get a tach or figure out your rear end ratio to see what RPM your running.

Re: 89 4 speed questions
 

My sm465 with a 30" tall tire and 4.10 rear gears would turn almost 3000 rpm at 65 mph.so I put in a 5spd and dropped it to around 2200 rpm at 65mph.. If you know all the info this is a quick way to find engine rpm............http://www.crawlpedia.com/rpm_gear_calculator.htm