I had a 1776 about twelve years ago, give or take a few years. It had dual 40mm webers, stock dual ports with heavy single springs, engle 110 cam, counterweighted DPR crank, lightend flywheel, 1700# pressure plate with solid disc. I had fun with that motor for about two years then finally, broke second gear in the tranny
. I guess thats what i get for using a stock tranny thats never been rebuilt in thirty years. Sold motor, and put bug on blocks until six months ago.
The dual carbs will by far, out perform a single carb. If you don't push the duals hard they get good gas mileage. As far as adjustments they can be a pain to keep in sync, if you don't have good linkage between them.
Dual port heads are far better than singles anyday!
A rebuilt stock tranny will work if you don't try and pull wheelies and do burnouts all the time. If you want to beef the tranny, steel shift forks,and welded third, and fourth gears, and a super diff should do the trick
.
Hope this helps.