In 1964 I used a small 2 GC Rochester (1-3/32" venturi) on a dual exhausted 194 Chevy ll with std shift and had no problems, used a homemade carb adapter on the very small cross sectioned 194 intake (later tried a 194 single bbl/intake on a 230-it did provide more low speed performance but naturally at the expense of top end-would only do 95 with 3.55 gears, would do over 100 with stock intake/carb and same fears, er, gears)
For exhaust on another Chevy ll I played with having a smaller than dime sized hole torched in the split manifold block off plate (under the heat riser area-I never split the exhaust into two separate manifolds always just separated the manifold internally-easier to manage during manifold installation) anyway by providing that small of a "balance" passage (rather than a full size "crossover pipe") the six still had the familiar rap, only it wasn't so sharp-more like a Porsche flat six "growl" even with short '53 Chevy (16" long) glasspaks in the stock locations under the back seat. Holes larger than the smaller than dime size would start to approach the single stock manifold/glasspak pitiful "wooosh" sound-so why bother?
From monkeying on MGBs and other old two outlet exhaust manifolded (old Datsun 510) four banger furrin stuff, it seems that if you can keep the two outlets separated 'till the pipes clear the engine bay and turn towards the rear (say maybe 2-1/2 to 3 feet from manifold) that even with a single pipe you will still hear the rumble/growl rather than the single exhaust "wooosh".
On some bodies running the dual side pipe can be a real hassle, but do strive to make both side as close (within a foot or so) in length or your "raaaap" sound will come out the two pipes at two different rpms rather than at one time in unison- can be "in stereo". My first Chevy ll had upwards to three foot or so difference in pipe length due to clearance problems with tight engine/crossmember/transmission (also had dual side outlet on front of manifold instead of more traditionally seen rear outlet) it all contributed to the sizable pipe length difference.
I have always used 2' dia. pipes on all my 194/230 stuff, did have a 2-1/2" system on a '67 half ton 250 with Hedmans/Flowmasters- Fats is right, the flowmasters do not sound so traditional-but I enjoyed mine settin' off car alarms with just a blip of the throttle-an' inna a parking garage a good "goose" would light 'em all up!.
