switching the diff and the ecu isnt going to do ANYTHING...assuming it was a turbo car to begin with....

the only difference in ecus is the atu oecu has the shift points...you arent losing anything by having an auto ecu in a manual car...

on top of that the diffs were changed by model NOT by tranny...meaning the diffs were 3.73, 3.91 and 4.3 the latter being the NA diff.....

finally....sounds like your car was thrown together ghettoly (yes thats a word) and thats a problem. that and you probably need some practice at the track....what were your trap times?