Ok so my 700r4 is acting kinda weird. When I accelerate hard the transmission will shift out of gear but won't shift up into the next gear. So it stays between gears for a while and the rpm's shoot way up into 5k. I'm thinking this can't be good for the engine. Anybody have an idea as too what is happening? And maybe a fix? I'm putting in a t56 soon hopefully, but I need this tranny to last till then.

Classic case of slippage is what it sounds like to me.

Ok any advice on what I can do about it. I've had the car since September but it hasn't done it until now.

Sounds like your gonna need your t-56 sooner then you thought.

if it is just a classic case of slipping. check your reverse gear, put it in reverse, if its still there and theres no delay in engagement you still have time, reverse is the only mechanical gear, and requires full line pressure for it, so if you ever get a car with a bad reverse(takes a while to kick in) chances are its on its last limps. anyways, give it a flush, most of the time that will take care of it. temporarily that is

Ya the reverse is good. Ever since I've had the car though it's really jerky when I change gears. Like going from park to reverse or park to drive. Even drive to reverse and vice versa. Is this normal?

my 89 rs did the simular to this, a few months later 3rd/2nd/ went. Still had reverse and 1st lol

Does you converter lockup when you put it in OD?
Low trans fluid can cause slipping as well.

sounds like your torque arm bushing, but then again a bad tranny mount can do the same

mounts clunk yes. late shift could be t.v. cable came off or t.v. valve stuck. governor valve stuck. mechanical problem like slipping clutches etc. You can check the governor by removing the small round cover on the drivers side with a screwdriver and pull out the governor, check for valve movement. Stuck t.v. much more difficult pull pan and valve body t.v. valve inside valve body likes to stick-aftermarket valves have a spring to help prevent sticking. Checked your trans oil level with engine running in park? could be.. fluid burnt? If burnt (probably is 1984) might be time.

When you pull the governor check the plastic gear too, seen a few come apart.

Ok. Well there's gonna be no car work for a while. Apparently we're moving to Texas. I hate it when my mom does this. I'm pissed so now would not be a good time to mess with a car.