My claim is based on this: If a 43mm single piston caliper can lock up the rear brakes (and it seems that when you disable the ABS it will do so) then you unquestionably have enough clamping force to overcome the traction capability of the tire on the road. Also, I have g-force data with 40mm rears and they show over 1 G braking vs. 0.8 G with the OEM size.
Is Dodge Racing missing something? (Is not SRT, PVO, Dodge Racing, and Viper all the same guys?) Ummm... they originally put the dinky caliper on the car. But no, there is a good reason for "elongated" calipers.
Anyway, I'm sorry if you don't get this from my discussions, but I thought I make it clear that the reason for larger calipers (2, 4, or 6 piston) is simply to use a larger pad. A larger pad will tolerate the heat build up, be more consistent over time and temperature. The pad material does not have the large temperature swings that a small pad would have. Or said another way, a small pad would have to be very hard to work on the track, and then be too ******* the street. On the track, a larger pad will last more laps. If fewer pistons could be used to apply pressure to the back of the pad evenly, it would be fine. (But in severe abuse situations, I think the slides (and their bearing surfaces) of a single piston caliper would not apply even pressure, so a fixed caliper is probably better.)
I jump into these conversations because people often think slapping a front caliper on the back is all they need to cure Gen1/2 braking. That's incorrect. I still have emails asking me (!!!) what is happening and it's because with 4 piston calipers in the back the system needs a proportioning valve to dial down the clamping force. Redsled, you must have done it properly on your car with the Wilwood 6 pistons in the front after putting the OEM fronts on the rear - but didn't you also add a prop valve? When you had the StopTech system on the Challenge car, you must have had a prop valve, too. Do the math (as shown on the StopTech site) and the physics shows that you only need (or can use) ~20% of the braking from the rear. Consequently, a rear brake that is nearly the same size as the front is tremendously overcapable and underutilized. Even in a real race car, unless half the weight is on the rear wheels under braking, you don't need as much clamping force in the rear.
While it may be somewhat impractical in the real world, I make the distinction between the size of the pad and the size (number of pistons) of the caliper. To me this is a worthwhile discussion for something important and so people can figure out how to do this.
Yes, I'm kind of over-explaining because besides being a Gen 1 guy with a good sense of humor, and I don't want to see A) people putting on mega-mega front calipers (like a 14" rotor kit) combined with the OEM rears, or B) mondo rear calipers (like any 4 piston deal) with the OEM fronts and think that's all there is to it. First it's getting the front-rear balance correct, then if you track the car, make provisions for higher temperatures.
Maybe you should come out to some of the events out at firebird and take your car through the course 20-30 times then you will know Bigger is much Better. 
ABS does what the valve does.
