I have recently put a new engine and trans in my camaro. The trans is a turbo 350 and the problem is that it shifts quickly while in drive, no matter how I adjust the modulater it shifts so fast you can barely feel the 1-2 shift and cannot feel the 2-3 shift at all. If I shift manually then it will pull through the gears to any rpm I want and hits hard when I upshift. The trans has a TCI shift improver kit and a Hughes 2500 convertor.I can also accelerate from a stop with the car in second gear it will then pull to a high rpm and shift late on its own and then I manually shift into third. Any help would be appreciated. Also the cam is a Comp Cam XE274 hydraulic which should have sufficient vacuum.

there designed that way to do that. Chevy figured that if you want to shift higher and harder than you would do it your self. Those fast shifts help to increase fuel economy.

Hello Houston,

You did not mention the shift cable that connects to the carb. The detent cable must be hooked up and adjusted properly. The cable should be completely tight at full throttle. The modulator has very little to do with full throttle shifts, because there is little or no manifold vacuum at WOT.

Larry

It sounds like a valve is sticking in the valve body. You might try a B&M shift kit. They have a little later shift pattern. You get later upshifts when manually shifting. Good luck.

You might check the governor and springs.

Sounds like some good ideas, I appreciate everyones help. I will give them a try and see what happens.