"Progressive linkage? We don't need no stinking progressive linkage !!"

Way to go, if you're going to mount them then they need to used.
20 mpg, hell I don't even get that going downhill in neutral with a 40 mph tail wind. The BB Olds (original 371cid) with the J2 option on a great day will only get 12, but on average it's more like 8 mpg. Could be the three old Rochester 2g's on the Offy manifold, or could be the lead footed 59 year old teenager behind the wheel!

I have been considering replacing my Edelbrock 600 and Torquer manifold on my 34 Plymouth with two Edelbrock 500's on dual quad manifold. 34 now gets about 12 in town and 17 on the highway, figure the dual quads probably won't dent it much more. Besides the next step after the dual quads will be the huffer if I can sneak it in without my wife knowing it.