I was looking around on the internet for an ecu replacement for my current l98 engine thats in my 91 gta ws6 and so far what i have found was this article back in 2009.to where this company named weswood came out with this retro kit for tpi engine to be able to use the lt1 pcm for sequential fuel injection and programing.

Have any of you guys heard of such a thing.the link and picure of the setup is at the bottom

 

Was probably feasible option back then but now outdated
Most would go to a LS1 PCM setup ; LSX tuners are on every corner these days.
http://www.eficonnection.com/eficonnection/24x.aspx

Why?
If you want flash tuning ability on your stock TPI ECM then this will do the trick
http://www.moates.net/ostrich-2-0-the-new-breed.html

Just plug your laptop in and change the tune ; even while driving

 

does this device works good