Just had a great experience with Jennings Race Performance and wanted to let you guys know. Chris rebuilt my T56 the way I wanted at a great price and truly stood behind his work with some of the best post-sales service I've ever seen. Here's what Chris did for me:

To save time, I opted to buy a complete tranny and return mine for core. Chris was having some problems with the shipping company he normally uses and we were getting close to the end of the timeline we'd discussed. Rather than waiting another day or two to sort things out with the shipping company, Chris personally delivered the tranny to my house (3.5 hours away).

After driving the car for a while with the new tranny, I talked to Chris about an annoyance I had (3rd gear was a little rough to engage under certain conditions). He was genuinely concerned that I wasn't 100% satisfied and decided the best course of action would be to rebuild my core transmission to the same level and just swap them out, no questions asked, no additional cost. Not only did he completely take care of my issue, he also personally delivered the tranny again, helped me make the swap (he actually did most of the work), and then we both test drove it to make sure everything was perfect.

This obviously wasn't the ideal transaction for either one of us but I couldn't be happier with the product and service I received. Two thumbs up for Jennings Race Performance....they get my personal recommendation for anyone needing a T56 rebuild. Here's a link to their site:
http://www.jenningsengineering.net/fbody.htm