i want to thank you all so much! i at least have a basic understanding of how these work now. i went ahead and bought it. in fact he threw in another 3 speed, a 4 speed shifter, a 3 speed shifter, and some other trans parts with the 3 speed w/ overdrive unit- all for $50! so i feel like i got a good deal. i should have enough stuff to make my project work. this is going to go behind a 292. i am considering putting it in my 53 hornet, but might put it in my 63 c10 since i don't really need the compound gear in the sm420 that's in it now. i would really like the overdrive for my 64 wrecker but i meed the low 1st gear in it. thanks again, hr