HaHa.....just sold my Avant II ('79 with 19000 miles)....Course, had the Chev 350.....but even so, had the usual steering box leakage, grease falling off all the fittings, little differential drip, overflow from the overflow when it gets really hot, etc. Bought by a non-Stude guy and he can't understand why "everything seems to leak".
Missed a chance to buy an R-2, 4 speed '64 Avanti years ago.......it was a wild ride (bet it's worth plenty now);
On the ''57/8 supercharger set-up......I think they determined it had to be mounted on top of the engine, and with the variable-ratio pulley it was so long that they only had room for a 2 barrel.....the output hose is only about 2 inches long when you eliminate the overlap. By not using the variable-ratio pulley on later ones, they shortened the set-up by several inches and had room for a 4 barrel. (at least that's my guess - probably as accurate as my conjectures about 2nd gear starts).
No space issues on the few '54 Packards with the same 'charger, so they blew thru a pressurized 4 barrel. Gees, flathead 359 S8 with a blower - bet they got good mileage, specially with Ultramatic).
Sorry, Ford Guys......that's why we're called StudeNuts.