well it seams like everyone has there 2 cents BUT that bog/hesitation you get when you start laying on the throttle and the seconardies are opening is a LEAN BOG, the secondary carbs have no accelerator pumps so when those 2x500cfm carbs open up at the same time, that engine is getting a lot of extra air and it takes a bit for the fuel to catch up(the reason your primary has an accelerator pump). putting heavier springs in the seconardies will slow them and make the transition smoother. I have an LM2 in my car to watch the Air/Fuel and you can watch it go lean for a slit second