Check your trunk RPO code sticker (if you have one). It should say WE4 in one of the columns. The chassis is an '86 1100 (old 1052 motor). Looking to possibly go with the 1127, or maybe just back to the 1052. Had good luck with my 1052(bored to 1109 with Arias pistons) and a little nitrous. Motor just got tired after 4 full seasons of racing. Seriously though, check your trunk lid for the RPO sticker, you can tell exactly what your car came with from the factory by checking those codes. You can get a list of all the code meanings on gnttype.org under the resources section. On my factory window sticker, the WE4 option reads as follows:
special turbo package - incl's
3.8 litre turbo v6, air cond.,
4 speed auto. trans, "T" pkge.,
sport mirrors, gray bucket seat
with console, and exterior
sport package.
Sticker price in 1987---$18,068.00
OUCH!
Hope that helps! If it is indeed a WE4, Welcome to the club! Only 1547 of them were made.