I have a bad valve that's causing my 1984 subaru gl to mis on one cylinder. I have two questions, #1 can I get the engine out without needing to unbolt the trans and taking out the drive shaft? #2 would it be easier to just replace the head and if so can someone tell me how tight I need to get the head bolts? Thank you

You'll most likely need to pull the head to fix a valve. MUCH easier to do by pulling the engine, I would not want to attempt it in the car, though it can be done.

These engines are really easy to pull.

I have a whole good engine in donor car, I'm just wondering if I just switch the engines will I need to unbolt or do anything with the trans? Or will the engine just slide right back in place?

No need to unbolt the transmission. 4 bolts hold the engine to the bell housing, 8 more bolts hold the engine to the motor mounts and exhaust Y-Pipe..

You should be able to disconnect everything and pull the engine in an hour or two, depending on how leisurely you want to be about it.

trans can stay in place.

 

And being an EA81 motor.....It is actually VERY EASY to get the heads off in the car.  (EA82 and EJs are harder)

 

No need to mess with trans, axles, etc.....

 

just unbolt the exhaust, the bellhousing bolts, and the engine mount nuts from the crossmember (oh and the pitch stopper on top of engine)