quadrajets have theee worst secondary metering system on the planet which consist of a set of what I call 'piss tubes' and what others call spray bars.
The primarys are so tiny, which house large [compared to the primary venturi size] boosters which together give great low end/milage but offer lil cfm in relation to the secondarys huge flow..which only strengthens the argument for why the heck couldn't they of come up with something better than 'piss tubes' and no boosters..
If it wasn't for stock class/fast class rules they would have all been recycled by now, and rightfully so.
A thermoquad is better piece, and I still would not recommend it for what you are doing because it is to a ventilated dinosaur bone.
nothing meters as well as a square bore.
Yes you are able to more fine tune the cruise with metering rods.. but in the end you'll short power wise with spread bore.
How big a carb you can get away with [without sacrificing low end] will directly relate to tune/compression.
The cam already gives us a power band or rpm, so now it's a usage requirement.
How much initial timing do you run for right now?