the weber for a 20r also has the water hose setup, is the aircleaner a factory type or a small rectangular one? What I'm getting at is are there adapter plates between the carb and intake? I have a modded 22/20r that has had several adapter plate leaks, until I made my own plate.
I have a 22r with a 20r head on it. Never make this mistake in a 4x4. It runs like a crackhead from a cop in a celica, but the stress of the heavy truck stretches the long head bolts, and the raised compression warps the head. It makes 195psi. I've got 5.71's on 33's, and I can make a mark on pavement in 3rd. It launches with a 5.0 mustang, but runs outta go at 65 or so. I have to admit, it's fun, but only gets about 8mpg, and I've seen the tops of the pistons 6 times, and held'm in my hands 3 times, including the original build.
I also have a Downey cam(3rd model) and header, double valve springs from TRD, Wiseco pistons, sealed power rings, TRD bearings, bushed rods, full balance job, 3 angled stainless valves and 3 angled hardened seats, full race matched ports and polished, aluminum rockers, high volume, high pressure oil pump.
The truck is called a Trekkor

And as I said, it is fun, just expensive.