uncooperative trans

i just got an 88 sev6 5spd and it shifts like ass.
i replaced the clutch slave (there was air in the line that kept coming back) but it only helped a little. basicaly this car is the worst shifting car i have ever driven and i have driven some messed up cars. i also hear a clunk from the rear end when i am stopped and am shifting in to first. i was wondering if anyone knows of any quirks these tranies have that can be fixed or if my syncros are just F-ed. i know with DSMs people swear by penzoil syncromesh and i will give that a try but it doesnt look hopefull.

check the rear tranny mount on the transmission. if it is broke it will make all kind of shifting problems

Are you sure you have all the air out of the lines? If so, you might try using Redline MT90 gear oil. I use that in my tranny and it works great. I have also used it in my Z32 tranny with bad sychros, and the synchro problem went away. It's a bandaid, but it works. Definitely pay attention to Sideways' comment on the tranny mount. Also, there is a bushing on the end of the shift lever that can wear out as well. You can replace that and it should get rid of a lot of slop in the gears.

thanks for the advice.
you may be on to something with the trany mount, it does feel like something shifts frome time to time. i will check that out next time i get the chance, tell me more about this bushing on the shifter

it is a little plastic cup about 1/2 inch in width they are like $1 at the dealer