1979 vette low mph high rpms
 

Hey guys im a bit new at this and am looking for a little help. i got a 79 3 speed automatic. and i just restored it after having it sit for a long period of time. the issue im having right now is that by the time im in 3rd gear im hitting about 40 mph and am in 30000rpms. i know this is way off and something must be wrong but im not sure what… if anyone can help me out that would be great.

Are you certain that the transmission is in 3rd gear? Do you know the rear axle ratio? What torque converter are you running? Are you certain that the transmission is not low on fluid? Not much else to check.

I think you mean 3000rpm not 30000rpms,unless you have a jet engine under the hood,then alls good,but if you have a stock 350 something is amiss. Tach may be off,check with an external tach,(i.e. an engine analyzer) your speedo may be off,check while driving along side a friend and compare speeds.Tranny slipping? Jack car up in rear and turn wheel once and count how many times drive shaft goes around,aprox3x's=308 rear 3 1/2=3.55,4+=4.10,etc.Maybe some one put a 4.56 rear in your car.There are no's on the case that will Tell you.Are you sure it's going into high gear?

Sounds to me like its not shifting past 2nd gear. TV cables or vacum out of adjustment/ off?