If the Passon conversion is $4500 by itself, by the time you source pedals, tunnel, carpet, underhood linkage and brackets, none of which I believe are included in the Passon conversion package, it would take much to add an extra grand to grand and a half to an automatic conversion using new parts.

Yes, if you scrounge around, buy used parts and collect parts over an extended time frame, you can do it for much less. However, there are always a lot of guys willing to collect parts for 2-3 years to save a grand. Typically we see questions on here like I want to convert my automatic in two weekends so I don't loose any cruising time, how hard is it. If this is your modus operandi, then your are going to pay premium prices.

Similarly you can do the same with a T56 conversion. By waiting and browsing, I was able to score a small block to T56 bell housing for $150. Normally these cost $500+. 72Swinger scored his new T56 for $1700, which are usually twice that. If your a budget shopper, you have to manage time as much as money.

This is where budget wise, the T56 will have it over the Passon unit. The proliferation of T56s out there means you can wait out bargains. That won't happen with the 855 anytime in the next decade, if ever. There simply won't be enough of them out there for bargains to pop up. Sure, maybe is some one dies and leaves a garage full of parts that their kids unload cheap, you might score one for a bargain, but I'd bet those to be the exception.

If you have the ability to fabricate stuff, as there will be fabrication involved with a T56 conversion, then that also puts the budget column on the T56 side. If you don't have the time, skills, or desire to cut and weld, have a pedigreed car that would loose value because of mods, then the 855 will likely be worth the money and be a great value.

Its all perspective. Much like the great Mustang debate next topic over...