Two Questions:
1. are there any sources for turbo 3.1 parts?
2. what are the major mechanical differences between a stock nat. asp. 3.1 and the turbo version, i.e computer, crank, timing ect.

i am considering converting my nat. asp. 3.1 to a turbo and when i foudn that GM, Mclearen and ASC already did it i figured why blow a motor when i can just use a "stock" setup.  ok thanks to all who post

Wildwildwest

Jeff m would be the source for some of the best parts..  you can find his stuff on turbograndprix.com...  YES the turbo engine is different.... I don't know all the differences are but there many... I am sure some one here knows them all.... KCP

Engine:

3.1 L OHV Multi port fuel injected Turbocharged 60 degree V6  
SAE Net 205 horsepower, torque managed 225 lb-ft toque
8.8:1 Compression ratio
89mm bore x 84mm stroke
Garret T-25 turbo .62 A/R intake , .60 A/R exhaust w/ closed loop boost control and integrated waste gate.
Intercooled via Blackstone intercooler mounted left of radiator rear of A/C condenser
22lb/hr GM Multec Fuel Injectors
Hardened and rolled crankshaft
Forged Connecting Rods
Mahle Cast aluminum pistons w/ reinforcing steel ring
1.72 intake valve, 1.47 exhaust valve 2 valves per cylinder
Stock 3.1 Camshaft w/ flat hydraulic lifters
Water to oil cooler
High efficiency 3 row 17 fin per inch Blackstone Radiator
High Capacity Dual cooling fans

Quote from: 1trucavalierEngine:

3.1 L OHV Multi port fuel injected Turbocharged 60 degree V6  
SAE Net 205 horsepower, torque managed 225 lb-ft toque
8.8:1 Compression ratio
89mm bore x 84mm stroke
Garret T-25 turbo .62 A/R intake , .60 A/R exhaust w/ closed loop boost control and integrated waste gate.
Intercooled via Blackstone intercooler mounted left of radiator rear of A/C condenser
22lb/hr GM Multec Fuel Injectors
Hardened and rolled crankshaft
Forged Connecting Rods
Mahle Cast aluminum pistons w/ reinforcing steel ring
1.72 intake valve, 1.47 exhaust valve 2 valves per cylinder
Stock 3.1 Camshaft w/ flat hydraulic lifters
Water to oil cooler
High efficiency 3 row 17 fin per inch Blackstone Radiator
High Capacity Dual cooling fans

As stated on the turbogpgarage.com website  8)

and that Crank is the Same as in the Lumina APV, Pontiac Transport and olds van too.

from 90-92 3.1L

as told to me by a Cross refference to find parts.