Is the HEI external coil distributor from 1989 a decent one? Can say a MSD coil be substituted for the stock coil? This 454 will have 101cc heads, performer intake , headers and 268 cam. also would the distributor from a 1989 9c1 car be better than a suburban one or the same?Thanks for your help. Kevin

My 95 Tahoe has a divorced coil, we went with an Accel when we did the plugs, wires, cap and rotor last year. Starts and idles a bit better but we changed so much at once . . .

Is the advance built in the MSD unit? The 89 would have no vacuum or mechanical advance in the dizzy.

From about 87-up the small cap distirbutors with a divorced coil have no advance mechanisms built into them- all advance was supplied by the ECM. And near as I can tell they were the same distributor on all models of Chevy V8, regardless of application.

Thanks for the replies, so if I'm putting this in my 71 camaro a different distributor is needed. OK Kevin

Also, the 89 dist. was probably in a roller cam engine. I'm thinking the gear was a different type steel than used on the older flat tappet cams. Might cause some problems. I know that using an old dist. on a (factory) roller cam is sure a problem.