have 1995 lt1 formula: can anyone tell me, if I change from an opti to a reguler electonic ignitition dist, would I have to take engine out to put it in. and also what would be the best way to run the wires thru the computer(ecm). What mod to use etc...

 

Why ditching the opti? The opti is an excellent crank trigger. have you looked into a delteq set up? Im sure the cost of swaping to a SBC distributor (if it is even possible) would be close or exceed a multi coil set up.

To answer your questio, maybe you could retain your opti, retrofit the new distributor and sort up piggy back it off the OEM stuff so that they are running as separate units but only the new distributor is sending spark. But IDK how or where your would get timing or knock retard.

 

The stock PCM needs the low resolution pulse signal from the Opti to fire the sequential injection. I've heard of people mounting the optical sensor module from the Opti in a conventional distributor, but don't have a link to anyone who has done it.

 

If the manifold is setup for a dizzy, then it will go in with the engine installed... Just a PITA! You have to set the dizzy into the manifold, then carefully slide them both back under the cowl and set in place... then the hard part is getting the distributor to line up with the cam gear just right. You'd have to use the opti, ICM, and stock style coil to make the stock PCM happy, then just connect the coil wire to the new distributor for spark distribution.