[John Rogers]

The way I read the original post was he put the RennShift in but maybe not? Anyways if it was already in there then the clutch could be the issue and it is worth a look. I always set my clutch up to release/engage with 50% pedal travel. Many racers like more many like less and it depends on the way the parts are installed. As Dave noted the adjustment might be off due to just a single ny-lock nut instead of TWO. The tube can come loose at the firewall as he noted and several others: the cable reversing wheel on the trans might be failing if there is one, the cable can be stretching and even the clutch pedal bushing can have failed. I used a custom clutch disc and pressure plate made locally in San Diego so it was very light on pedal feel but was "instant" engagement, like in the 200 MPH 914 that ran at Bonneville with the nitrous Chevy Big Block in it and only 2 gears.
Anyways look closely at the other places I mentioned and if they are suspect then replacement would help.