I just purchased a t5 and on the 235 clutch housing i did not need an adapter. I think only a spacer is needed if you do not cut the shaft. If you you get a t-5 try and get one from a v6 and make sure it has the mechanical speedo. If you search this sight it has many posts and some articles in the tech tips on t5 conversions

"As I lay rubber down the street, I pray for traction I can keep, but if I spin and begin to slide, please dear God protect my sweet ride." -Amen

56 Chevy 3100