So i have 85 chris craft scorpion ltd w/ alpha1 gen1 drive, 300 tempest MerCrusier motor and has a 144 b&M supercharger on it. The motor had some issue's last year with vacuum leaks and what i thought might be the distributor which was the stock merc thunderbolt IV. i fixed the leaks and switched out the distributor for a MSD HEI. The motor runs greats now. I went to launch it and i could only go in reverse, so i took off the shift linkage. I was able to manually make it go in forward and reverse but not with the shift cable connect to the throttle. I spent the next few hours trying to adjust the shift cable but never could get it just right even after setting it to the stock measurements. Could this problem be the shift cable or could it be because the distributor does not kill the motor when it shifts between forward and reverse.