I just need to know what RPM an 84 z28 automatic 4speed 305 HO should be shifting at? when i got on the highway today, it was in 3rd waiting to shift into 4th right around the 3000 or 3500 mark steady. I didnt have it floored and I really couldnt keep that speed up or i would have smashed into the person farther up in that lane. what i need to know is what RPM does 3rd shift into 4th? I think it was a case that i just didnt have enough throttle on to push it over the mark. i'm curious though. Thanks.

 

It depends, on alot of things. What speed you are at, are you going at WOT, in which case most wont shift into 4th unless you have a full throttle overdrive valve. Also age might affect shift points. I know my 86 with about 120K miles on it shifted rather sluggish, where as my 89's 700R4 with about 15k miles on it shifts perfectly. If you leave it in 4th going on the freeway and you're not pushing it too far, you should shift into 4th at about 35-40mph... Figure thats about 2500 in 3rd? Someone else im sure has more accurate numbers, im just guesstimating

Will

 

my car has almost 83000 miles on it and it shifts smooth and strong. i wasnt at wide open throttle so i'm assuming it seemed like it was "stuck" there.