I have an 88 305 TPI trans am that I was going to replace the distributor on. I removed the cap, the hold down bolt, and pulled the distributor up about a quarter of an inch till it stopped and wouldnt pull out any further and then i remember I had to mark it. I cant remember if I turned the distributor once I pulled it up. I pushed it back down and it seemed to lock into place. Did I mess up the gearing? It was only able to pull upward between a quarter inch and half inch, I just cant remember if I turned it.

 

You didn't pull it up enough to separate the gears, so mark the current position of the rotor, and install the new distributor with its rotor in approximately the same position.

Even if you messed it up, it doesn't matter so much. Marking or turning the distributor housing doesn't matter because the new distributor won't have exactly the same phasing between the gear, rotor and housing as the old one. You still need to time the engine afterwards regardless.

 

How high would the distributor have to be pulled up to seperate the gears?

 

If your replacing the distributor it won't matter if you marked it or not. You'll still have to retime your engine. Its not to hard though i did mine in like an hour.

 

Well I decided to hold off on the distributor and I dont know if I seperated the gears if it was pulled upward an inch at most and then something was stopping from from pulling up any further.

 

You probably didn't mess up your timing then. Easy way to know is try and start your car. If it doesn't start and backfires then your timing is messed up. If it starts and runs like crap its messed up. If you get it to start go and drive it around give it full throttle and see if the vacum or computer advance will advance your timing along the rpm band range. If you hear pinging or backfire as your rpm's go up then just turn your distributor housing a little each time till you get it to sound normal. Or using a timing light makes it much easier.

 

If it dropped right back down fully then the gears are in the same position. If you'd pulled it up far enough to separate the gears, the oil pump drive would have been misaligned.