"turbosedan" posts very regularly at the w-body.com forum. You might try sending him a PM on that forum and trying to get help there. FWIW, he has a dark blue '91 Cutlass Supreme with a 282 5 speed and a 3.1 with a turbo 3.1 setup on it. I don't think he has ran it at the track, but I do remember it did something like 227whp when he dynoed it and i think over 300ft.lbs., and I know he also said his first gear and a lot of his second gear is useless.
The engines are basically the same. It depends on what literature you read, but the bottom end might as well be the same thing and the only real difference is the turbo engine got larger chambers in the heads for lower compression (8.8:1 in the turbos as opposed to the 8.9:1 of the regular 3.1
). Obviously that difference is basically nothing so that doesn't really matter.
If you can find a complete 3.1 turbo setup, you can bolt it on to your 3.1 and have no real issues. You'll also need to use the ecm from the turbo engine as well. The problem is that you have a 5 speed car so you'll need the chip programmed for that as well since all 3.1 turbos were autos originally (other than prototypes).
Hope that helps.
1990 Maroon Grand Prix STE McLaren 3.1 Intercooled Turbo, 14.695 @ 94.49 on 12psi before cam/heads/etc.
1990 Bright Red Grand Prix McLaren 3.1 Intercooled Turbo, 14.819 @ 92.72, 189whp
1999 Grand Prix GT 9.75:1|K&N|160 tstat|No Ubend/Cat/Res|UD Pulleys|Ported M90/TB/Heads|XPZ|2.55"|Pacesetters|Stage 2 I/C. 12.442 @ 112.78
2000 Blue Bonneville SSEi Supercharged Gutted Airbox|K&N|3.4"|1.9'*|WP Pulley|Custom DHP|180*stat|41932'*|No Cat. 14.681 @ 94.80
2002 Dark Cherry Grand Prix GTP Supercharged & Intercooled
12.084 @ 114.38 w/1.743 60', 315.6whp, Fastest Stock Cam M90 GTP!
NOW XP CAMMED, 340.6whp with XP, stock heads, Gen 3 M90, 11.984 @ 115.84 w/1.750 60'!
Most HP Stock Heads Gen 3 M90 GTP!
2004 Red Monte SS Supercharged K&N|3.4 Pulley|1.9'*|180*stat|41919 plugs|3" dp|No cat/ubend|DHP|Shift Kit. 14.2 @ 98
GOT BOOST??? Friends dont let friends drive stock!