...well, sort of--at least this sounds right. In truth; you're not really controlling optispark since the optical element of the distributor is no longer used--but the distributor is. I've been looking into this for quite a while--I'd just basically like to retain EGR w/o rigging up some sort of remote style system like the TPI Vettes.

The distributor portion of optispark can still be used. I'd mount the TPI HEI module near the optispark somewhere--the only thing you are missing is the trigger. I originally looked at the possibility of adapting a crank trigger mechanism but I still don't know what the store bought ones like the MSD output & if it can just be a plug-in (I doubt it). I also looked at creating my own crank trigger system with a custom machined crank wheel and the pickup off the distributor (I can get this made for free at work), or seeing if I can fit the stock stuff into the opti-distributor in place of the opti-stuff (I have no idea yet, the opti is still on the motor, I haven't even looked at it yet). Or, you could get the trigger signal from the GM GEN II crank sensor that was used on LT4's (I think). I have a feeling that the sensor, timing cover, and hub will co$$$t you though.

The optical portion could be used if you could somehow come up with a "reluctor" disc 8 slots spaced 45 deg. apart to create an output similar to the HEI reluctor. I'm sure it could be done, but then it seems you're stuck with the reliability issues of optispark but without any benefits.

Either way, you'd need to phase the trigger with the rotor properly ( I think you'd have to trim that wide-*** rotor tip too) and index their positions accurately in order to be able to set up timing. The only thing you lose is the ability to alter the base timing under the hood (big wup).

Why? ...Heck, why not? The way I see it, the worst part about it is the cap and rotor change would still be a pain (only versus the distributor mod; optispark guys would still have this trouble). For those with the 7730, harness splicing is eliminated, the only splicing is a couple of the module wires.

All comments welcome; am I missing something?

 

wouldnt it be easier to run the motor off the rear distributor and batch fire then deal with the opti?...

you sound like you researched this thouroughly so theres nothin more i can add..i carbed my LT1 motor lol

 

Heck, if I lived in Michigan I'd run a carb too. I love EFI, but hate how much it costs. Did I say hate? I mean LOATHE.

The 7730 ECM IS batch fire, its the original TPI computer, and no gen I SBC f-body TPI was sequential from the factory.

Running a distributor is probably what I'll do; plus its been done
so there shouldn't be any unforseen problems.