When I first got the car it wasn't going into 3rd or 4th at all. I changed the fluid and filter, threw in a little Trans X and to my surprise it started shifting through the gears. The only problem seemed to be that it slammed into gear and threw my head back in the seat but it kind of reminded me of the way I used to drive my Mustang so it didn't really bother me. I haven't driven it much since, just around the block for test runs after fixing stuff. Today I took it for a longer drive and encountered some weird shifting. At first it was slamming through the gears as usual. But after about a mile it didn't really want to go into 3rd but finally around 4 grand it slammed into 3rd. Then when I accelerated from a stop it was revving to 3500 - 4000 before shifting into 2nd and 3rd. Also, when I let off the gas at high rpm's it doesn't downshift. I know that need to check the vaccum valve levers and look over the vaccum lines again (they looked good before). I'm also going to flush the transmission and change the filter and fluid again for good measure. Is there anything in particular I can check in the transmission while I've got the pan off? Could the bowden cable adjustment cause these problems?