running rich

i just recently installed an msd opti, new plugs, coil and 8.5 msd wires. i allso installed a new timming chain and a new cat . my car still woud not start. turned out my ICM was bad, replaced that towed to muffler shop for new high flow cat. on the drive back i noticed my car was down on power and running on the rich side. my dumb ass didnt take the time to fab a timing mark for the new msd opti. would appreciate any pics from anyone who has fabbed thier own for ides. I also would appreciate any ideas as to what would make my car run rich, i suspect the timing is to far advancded. it idles and revs smoothly just down on power like spark is advancing to much any info would be great. I usually dont ask to many questions because if i reasearch enough i usually find the answer i am looking for, not the case this time.

Thanks in advance guys.

What year is your LT1 engine.... vented or unvented Opti? If unvented, are you sure you got the Opti drive splines lined up correctly, both in the cam sprocket and in the back of the Opti.

i have a 95 with the vented opti, sorry i haver never gotten around to include my mods in my signature