Shame you aren't using a OBD-II PCM. My computer is in a box with a tune for a CC306 6spd which I could lend to see if that would make any difference. I think your issue may be the tune but PCM4Less has done those before so I would imagine they are using default values. As mentioned, start data logging and report back. No need to drill a hole in the TB.

Funny how LT1 intakes have IAC passages, and LS1's don't.

Funny how chasing split BLM's for all eternity from a hack job is fun.

Yea, youre all right. Hope all you experts can help Ted out then. Good luck

I found the schematics to cross reference the LT1 to my 12 pin diagnostic port so I'll be all set. Even have a windows laptop to borrow for logging. What software do you guys recommend I dl?

PCMforless told me it's a very common setup so they already had base figures they used, supposedly...

Stay classy. What are you accomplishing or improving by drilling holes into the throttle body?

Need some datalogs before we just start throwing parts or drilling stuff.... :)

Update - The car runs perfect!

I wired up the diagnostic port and tried to datalog but I couldn't get a signal (which could be security on the work laptop) At the same time I was doing research and the problem sounded like a VSS issue. Years back when I swapped in the T56 I had the tailhousing machined to accept a mechanical speedo drive. I assumed this replaced the VSS. Under this assumption, when I swapped in the LT1, I asked PCMforless if the VSS could be tuned out along with other things on the build sheet. After reaching out to the tuner, more research, and actually looking under the car, i saw the vss right next to the speedo drive. So I bought a connector, wired it up, and it ran perfect tonight. I guess I thought the VSS was the skip shift or something when I put the trans in :doh:

I also got my wipers working too, great night!

Good stuff, thanks for the update.

Not bad!