I was driving my 91 back from my friends house last night when I was doing about 90 or so in 6th the tranny starts bucking and making some kind of grinding noise and would not let me increase speed. It stopped when I let my foot off the gas but when I went back up to that speed it did it again. Again it went away when I let my foot off the gas. Not sure what that's all about. Wondering if anyone has a clue. Also was going to replace the stock hurst shifter with a pro 5.0 and when I pulled the stock one out and went to replace it the base plate on the 5.0 is larger then the stock hurst one by about .5 inch??? The box says it's the right shifter for a T-56 from a 93-97 F-body. Not sure what to do. John said we can fab a gasket for it if need be, just wondering if anyone knows anything about these problems. Any suggestion would be appreciated.

 

You were trying to pull in 6th gear? Not gonna happen. The engine doesn't have enough grunt to pull a 0.50:1 gear ratio. Even with a 4.11:1 rear gear you are now only effectively using a 2.055:1 ratio. My car only turns about 1,900 RPM at 80 MPH in 6th gear. There's no way it can accelerate from that RPM. 6th gear is for gas milage only. Also, trying to make the engine pull in 6th is beating the snot out of the bearings. Eventually this will cause damage.

Do the bolt holes from the Pro-5.0 line up with the shifter bolt holes on the trans? My Pro-5.0 hangs over the edges a little. That's normal. BTW, no gasket, use some Ultra Black silicone. T5s and T56s don't use gaskets. The case and everything is sealed up with silicone right from the factory.

 

That makes more sense, I still only have my stock 305 TPI in there, haven't put the new motor in yet. Also the bolt holes do line up on the shifter, it just hangs over a little, I want to make sure that was ok. I'll definately take your advice about sealing it. Thanks for replaying, no one was and I was starting to wonder if I had some kind of anomoly!

Chris