Plug-n-play distributor & ignition box

"Dizzy." yeh. What is a "mechanical" distributor? You mean breaker point distributor? If it is already breakerless, with a 6AL, you might not gain anything, unless it's worn out.

Post your MSD part no, like 6420 or whatever. Go to MSD and download the proper destructions for your MSD. The diagram to interface to a Pertronix is right in there