I've written about this in my Member Project but, I though many others might be interested in doing this.
I bought the TR off Brent's JJ and while doing machine work on it, I found that the bolt pattern, for the top plenum, was the same as a 4500 Dominator carb and looked like one would fit the lower manifold ports. I found a 8896, 1050 cfm carb, at a swap meet, about 3 mo ago and confirmed that they will fit w/o any throttle interference to the manifold but, I thought it might flow better if a spacer was used, to straighten the transition, to the TP runners. So, I made two 3/4" spacers, with 2.03 bores.
Another problem that reared it's head, was the intern, progressive linkage. They make a 1/1 & 2 styles progressive, my 8896 has what they call a "soft stag", the other is "Staged". The Staged is for 4v application and the Soft staged was developed for 8v applications ans starts opening the secondarys, at 15° as opposed to about 37° of the staged linkage. Now the easy thing to do, is to replace the throttle linkage to the 1/1 but, those little things, believe it or not, are up to $75 each......
I decided to try a a slot in the spacer, about .20/.30 deep & angled to connect both sides, for that first 15° of opening. 1/1 linkage, uses .028 squirters and progressives linkage, use .035's so, I'll replace the secondarys with .028 and leave the .035's in the primarys and see how it works.
It seems more than a coincident that the Weiand TR has the 4500 bolt pattern for the 4150 plenum, did they ever sell a upper manifold for the 4500 carb?
Here are some pictures.