Tracy;

"Height"/length of relaxed springs will answer question if they are the correct ones...lay them down and measure, and compare to what they should be (unfortunately I don't have the reference info)...I just measured the one in my "training carb" to be 5 5/8"/140mm...use this dimension as a guide, not gospel! I can't guarantee it, and remember your carbs are the clones which MIGHT also have differences...you might at least compare the Hit to SU spring lengths...they shouldn't be too different... I expect too strong springs to cause lead stumble on fast accel only, not slow accel and after steady state is reached.

Remember also that unloaded, in the driveway, those Dashpots won't rise so much because demand is not there...under load driving they will...you're idea of watching them with camera along with WBO2 gauge is a good idea for data gathering...

another idea...but I suppose elec FuPu MAYBE already answered the starvation question already (BTW, did you supply it through pipe from tank? even elec FuPu can't supply fuel to carb that it's not able to get (clogged supply line or I've heard of in-tank line being corroded off)...you could supply it by hose into a fuel jug in the passenger seat floor to completely take stock arrangement out of the picture...): when it sputters, shut off engine immediately, pull over, and check levels in FuelBowls...if you catch them low, that again rather confirms starvation...so the suspicion would be off the carbs, because they can carburate what they are not getting supplied with...

Good Hunting!