The off manifold has the q-jet bolt pattern but needs a little clearancing for the q-jet butterflies. On my 72 I've got a 351w, offy manifold, q-jet, with an Edelbrock elite triangle air cleaner and a 2" body lift to fit under a stock hood.Weiand if I'm not mistaken is the only manifold setup for the qjet bolt pattern. The qjet is the best for off road as far as 4bbl are concerned.
Yes you can use an adapter in the others at the cost of height and potential vacuum leaks.
I run the same setup on my 70. Once you tune the AVS carb, it runs great.I did the 2bbl to 4bbl switch about 6 years ago when I first got my bronco. Edlebrock performer manifold and 500cfm avs2 carb. Fit fine no body lift at the time. Wish I had just kept 2bbl carb. My 302 doesn’t make enough torque and hp to need the 4bbl and don’t drive it hard enough to need the 4bbl.