The back spacing is what really makes them different. I think the toque thrust comes in a darker colered center than the vintage wheels. The 45 or the 40 has a straight spoke and the other one is cuvred.
First difference is SIZE. TTD's don't come in 16". V40/45 ONLY comes in 16" (soon to change).
The Vintage 40 and the Vintage 45 are very similar to each other. In fact they are identical in every way but one. The spokes on the Vintage 40 are straight and on the Vintage 45 the spokes curve out then back in. This is how they received the “D-spoke” shape name.
In addition to the above: the Vintage 40s and 45s only come in 8" width for now. My impression too is that AR is not much interested in providing for various customer requirements when it comes to the TTD - sure you can custom order two piece clones from them in different sizes and b/s but they don't make it easy. Vintage Wheel Works, OTOH, has been a pleasure to work with and are powder coating the spokes on my V45s to my specification as we speak.
Both wheels look fantastic, (IMO) but the finish and quality on the Torq-Thrust is much better (Again, IMO). Center caps are not interchangeable.
A friend has a set of Vintage 45's on a GT350H (17"). One tire would leak down over a week or so, the leak was coming from the wheel. Dealer refered my friend to the manufacturer, manufacturer said go thru the dealer....
Let's see -- TTD's have only 3.75 " backset - won't quite allow the maximum tire size you could otherwise run. Vintage 40's & 45's are a perfect 4.25 ", it will USUALLY allow a full size (i.e. 225 vs 215) larger tire without rubbing, all things being equal. They are currently only 16", not a big deal since a lot of guys (and gals) run 16's anyway. My TTD's are 15", by choice. I understand Vintage is adding new sizes soon.
TTD's are better finished, and yes, you can get accessory center caps for them. See Cal Mustang's catalog for them. "Lolita" has 'em, and they're nice, very nice.