I've been planning on rebuilding due to its 215,000 miles L. I just recently purchased a supercharger off a 95 Buick 3.8L for $50. Bought it just cuz, but now I’m thinking that I should try and custom mod up blower system for my 3.1, using the M62 (I believe Gm switched to the M90 in 96) which flows 600 CFM at 16,000. Also I purchased a turbo out of an 89 thunderbird 2.3 motor, again for no apparent reason other than it had 40,000 miles on it and it was $80. So my question is what would be the best setup, super, turbo, or twin, and what would necessary upgrades to the fuel injection be, also what kind of custom modding has been done before with these kind of setups.

Specs on my turbo:

Warner-ISHI RHB5 Specs:
Air Flow Rate: 1.4 - 10.8m3/min // 49.4 - 381.4ft3/min
Max Pressure Ratio: 2.8
Maximum Speed: 180 x103rpm
Max Allowable Gas Temp: 9500C // 1742oF
Diesel Engine Application: 54-154Ps
Gasoline Engine Application: 73-208Ps

im not sure the 3.8 sc will bolt correctly to the 3.1 engine.
may not be same bolt pattern, and even then u will have to reconfigure the serpentine system to drive the blower correctly. the turbo is way too small even for a stock engine.
i would recommend u rebuild your engine, and fabricate a single turbo system. a mpt70 will make all the power your engine can handle.
with 42lb. injectors and fmu, it will support around 300-350bhp

The Supercharger will not bolt to the 3.1l Mounting flanges are different, between chevrolet and buick.

u can build an adapter to bolt that supercharger onto the stock lower intake and would prolly be the cheapest way to go.

other then that ur other option is a turbo, but the one u have is to small and a mp t-70 is way to big i run a 61mm turbo on my 3.1 and even that is slightly on the large side .

a t3/t5 hybrid 50 or 57 trim is ur best bet with a turbo