will a 1999 regal gs transmission fit in a 2001 grand prix gt?

both have 3.8l v6s i forgot to add as well

do you know if the axles are the same size? honestly my only concerns are matching bolt holes going from a l67 to a non supercharged block. and if i had to buy new axles. any tips on what to replace on it before it gets put in for a longer life span of the trans

The blocks are the same and so are the transmissions. The supercharged one has heavy duty internals and may possibly require axles specific to a supercharged application. Just look at part numbers for the two cars and the supercharged/nonsupercharged cars. Also the electronics may be different between the two years so you’ll want to confirm that too.

Yea you can use alot of parts window motors there both made by gm. Genric motors almost everything but body's same exact car some stuff may be in different places. I have 98 gtp supercharged 3800 and 2000 regal gs supercharged 3800 regal hydrolocked 3 times finally went out little over 400000 miles so got gtp and keeping regal for parts maybe rebuild and make one a performance street car. In few more years bet people will b wanting these cars aging. To much technology in new junk!