Frank, I did the controversial T5 swap with my small block. I drive it like i own it, so it's no muscle machine and doesn't require a bulletproof transmission. Over 95% of the driving i do is on highways, so my objective was to both lower the engine RPM as well as provide better fuel mileage. T5's are a dime a dozen and clutch packs are available pretty much anywhere. When it's all said and done, I spent about $650 Canadian (so like 100$ US
). I as well wanted to retain the stick, so i chose this much more economical route. At 65 mPH, I'm now revving at 1900rpm running 29" tires. The amount of work is slightly more with the fact that you need to get a new clutch, drive shaft needs to be cut, and you need to cut a new hole in the floor for the new shifter location.
If at a later time i fully resto this truck and drop in a big engine, I'll get a Tremec...but i'll likely win the lottery for that one.