I have a 69z28 with a 350/330ho muncie m-21(rebuilt by jt's muncies) a borg warner clutch and 4.10 posi 12 bolt. the shifts good both on the street and at the track. When I race the car i can't push in the clutch to slow down until I get down to about 75 mph. I go thru the lights at 104. When I push in the clutch at that speed it gets loud, and since my transmission blew up earlier this year I get worried about noises. If I let the car coast down to around 75 it seems ok but this can't be good for the motor. What does everyone else do?

Dave,
What clutch (brand & style) do you run?
Chris

My clutch is a borg warner 10.4 inch Diaphram style with about 5k on it. I think a better clutch would probably solve this but funds are a little short after rebuilding the muncie.

Dave,
You can depress the clutch to make high RPM shifts, but can not depress the clutch at the end of the track?

Could this be a clutch linkage/throwout bearing binding problem?
Chris

I have a M21 with a Centerforce Dual Friction Clutch/Pressure plate and a 11 lb Hays alum flywheel. 12 bolt with 4.11. No problems with clutch at low or high speed (115 mph)
I do, however, had to pay attention to clutch linkage throw - too much and the pivot arm goes past even for the pressure plate diaphragm fingers, so I had to adjust the rod so the clutch pedal engages closer to the floor.
I also had to pay attention to clutch rod tweaking when the engine torques over, primarily at 1-2 shift after a hard launch and at 6500 rpm shift. It seems the engine rotates enough (poly motor mounts) that the clutch linkage prevents a smooth push back when the pedal in engaged. I had to build a turnbuckle that attaches to the frame and the cylinder head to keep the motor in place, rather than using a solid motor mount. I then disconnect it when running on the street.
Good Luck.

Thank you for all the suggestions so far. I checked the linkage for binding and so in everything appears fine. I did have to re-adjust the clutch after the last 1/4 mile runs. I t shifts perfectly at any rpm. I just can hold the clutch in at the end of a run while decelerating? Does this help any? Thanks agaon for all your help so far.

To each their own at the end of the track.

I like to clutch my car at the end of the track and use only the brakes to slow down. On the other hand, my father likes to "engine brake" his car and leaves it in gear and gets out of the gas to slow down.