rebuilt no 3rd or 4th
 

i have a 93 z28 with the 700r4(4l60) and after a rebuild i got no 3rd or 4th. i have checked the fluid level and it is ok. any one got any ideas. it does shift into 3rd but just slips and the rpm go crazy

Since it is trying to shift a torn seal during the install is the most common issue. You could have a sticky valve. Checking line pressrue while the car shifts into gear could give you a clue but I would pull the valve body and go thru it before I pulled the tranny back out.

Oh that dose assume the accumulator is together right. Did you do the tranny yourself or have it done?

i had a friend do it that i thought he knew what he was doing. but end the end he did a real crap job. i was able to pull the out put shaft out by hand. so i think i am going to go with my other option and i put a tranny in it that came out of a vette. i am going to have to come up with a way to make a rear mount but i dont think that should be to hard.

Your going to need to build something like this. My homemade torque arm relocation bracket. What yal think - LS1TECH

Remember your drive line angle is very impotant. If the angle of the drive shaft is off even one degree you car will shake at 50+ MPG.

Hey, if I could get 50 MPG out of a Camaro, I'd put up with a little shake! ;)