I think once everything's totted up, you may need to set a kidney aside. It's an expensive exercise...both worth it.
28 vents are probably too big for a 1600 but you need to know the inlet valve size. For bus engines that need torque at low revs vents 4 to 6mm smaller than the inlet valve diameter are about right. If the vents (or valves) are too big air-speed at low revs is reduced which makes tuning more difficult – or impossible. The size of the outside of the carb doesn’t matter much unless you want to impress the guys in the pub.
Although Dell 40s are the same casting as 36s it would be more likely to come with suitable vents etc .. plus I hate a big mismatch to filter and manifold ...36s are good up to 2ltr
It's a 1776. Valves are stock 35.5mm, so maybe 30s (I have a set) would be better...but I can't be a*sed to change them from 28mm. I like 'em strangled. It's certainly not short of grunt.
