The best place by far for me has always been
www.moderndriveline.com 
with
www.darkhorseperformance.com in second place. I say this after using them over 5 times for different projects. Make sure you buy a tranny with a shortened input shaft instead of a standard trans with a bell housing spacer. Check them out. If you need any more info/advice, just let me know. 65-73 Mustangs are my bread and butter.
