OPS. 67's.... man,,, I have run every iteration of carbs known to man on them...
OS, K&B, Picco, CMB, RPM, C/B jet ring, Speedmaster, Tidewater, ARP, Ernie Lafleur, Carbs machined locally in Houston....
Pretty much if it had a carb and could be machined to fit, we tried it. If not, we just machined the back of the carb flat and made an adaptor.
2-56 machine screws, a tap and JB weld were our weapons of choice...
The stock slide valve IS hard to beat in a scale, and mono's if you like using LSN's... I typically never ran them in my riggers,, I actually preferred CB exhaust throttles, with a venturi, spray bar and 3rd channel mixture.. K I S S.
Rotor clearance is a big factor...spent many an hour lapping in rotor disks with very fine compound followed up with Comet cleanser
to mirror polish the final fit, and set the disk to just float on a layer of oil....you knew you had it right when you could roll the engine back and forth quickly past the opening of the intake and be rewarded with a loud POP !
It's kind of a lost art today,,,
but I still have a bunch of OPS stuff,
and my secret stash of old carbs..
As far as bigger is better? It's kind of wasted on OPS, as you are limited by the opening in the rotor housing anyway..make the stub on the carb to thin, it will be crushed by the lock bar and fall off...or worse, just crack and fall off.. after market housings can be found and can be machined larger, as well as drum rotor conversions,,, but now your moving way beyond just sticking a different carb on a stock motor...
