The only reason I am aware of the conversions having been done is because I have seen conversions for sale occasionaly.
The drivetrain is more than likely able to handle it, especially since it is basically the same transmission used the the Porsche 928. The Porsche has a different case to allow for the rear mounting and diffenential integration, but the innards are mostly the same. Some 928 tuners have claimed 400+ rwhp without problems.
If I were to do a chevy conversion on any car, I would probably want to use the R700 transmission with the locking torque converter anyway. This would simplifly installation, leaving only custom mounts and a custom driveshaft.
If you want a car with more power, then why don't you just get a car with more power? A conversion could cost several times what the car is worth, and create alot of downtime. Something like an 80's or 90's Mustang offers impressive 0-60 times, plenty of tuning options, and is cheap to buy and repair too.
\'87 Mer-B 300D (220,000 miles) (sold)
\'93 Mer-B 300D (173,000 miles) (sold)
\'87 Porsche 928 (101,000 miles)
\'98 Dodge Ram quad-cab (250,000 miles)
\'2001 CLK430 Cabrio (50,000 miles)
Past cars: 1969 mercedes 250, 1981 300D, 1972 220D