this TR has had the two halves matched to each other, and has been gasket matched as well.
the Holley SD has been made into a 4500 intake by welding a plate to the top of the plenum, and then blending that into the original casting, however it has not had any work done to the runners themselves.

the STR-14 had the mods recommended in the old DC engine book done to it, which the owner says were worth almost a tenth in the car.

if you look in the tech archives at the original Ebrock head tests, you'll see the TR was better than the Holley 4500 on that motor by about 20-25hp(same two intakes).
so, it looks like as the power level goes up, the TR starts to show even more promise.
however, on that test i was using two modified Speed Demon 650's.
ive since sold those carbs, but am going to get together a pair of ProForm bodied carbs for future testing.
at some point i'd like to test the Weiand TR against the MP TR(which i have as well....but it needs a little tweeking before being put into service).

on a 528 with BS heads, a "cleaned up" MP TR with 2 X 750 Holleys kicked the crap out of a single plane M1 with an 1150 carb on a 4150/4500 adapter by about 60-70hp IIRC(i'll have to check my notes).....so i think it might be a pretty good piece.

EDIT-just checked my notes.....the MP TR was 50hp better on that 528. 690hp vs 740hp, and the peak TQ went from 690 to 715.