I saw this and it intests me. Since I'll be installing the LT1 soon, I'd like a way to get around using the Optispark. For some reason it won't let me copy the exact address. Just go here: http://www.dw-zone.com/ click on hobbies at the top of the page, then scroll down to the bottom of the page and click on LT1 to LS1 Coil Conversion Page

You still retain the opti with that system it just no longer carries the spark.

It just uses the optical section of the opti for the coil pack conversion. I have helped 2 guys her in TN install one on their cars. If the opti optical section is bad then the car will still have issues. There is another option out there that is based off the magnetic crank trigger system. It uses Northstar coils w/ 2 cylinders per coil.

Bob Bailey makes the LTCC box which converts and splits the optical signal from the opti into the signal for the 8 coils in the LS1 conversion... Its a pretty good setup.