In following another post on related problems it has made come up with some questions of my own that I hope members may shed some light on.

When reading the writers issues with idling, running rich etc. it got my attention as I am preparing to install a disc brake conversion on a 1968 383 Camaro. I have already purchased a complete power kit from Right Stuff with 11-inch booster and 2" drop spindles. With a pretty radical Lunatti hydraulic roller, I am wondering if I will have a vacuum problem powering the booster. The engine has World heads (220 Motown) Steel heads and tall valve covers. This I am now afraid may make the 11-inch booster the wrong choice as it may have a clearance problem with the valve cover.
Questions:
A. Will the nine-inch booster perform as well and will it take less vacuum to power it?
B. With 15 x 3.5 draglite front wheels will I have a tie rod clearance problem with the front wheel by using the 2" drop spindles? I am replacing springs with stock height.
C. I am not familiar with the vacuum can set up but is this a sure fire way to solve the problem, I do not want to spring for a 3-400 dollar vacuum pump.
I plan on changing all this out this winter when the car in the stable, I should have checked this out before the purchase but since I have not unpacked the items, I though I may be able to trade items with Right Stuff if necessary. My 650 dual pumper has a vacuum port at the front base of the carburetor and a performer intake. Is this the best place to check engine vacuum? I can not use a 1" spacer as someone suggested with vacuum port due to hood clearance, I am running a 4" K & N, and I had to use an offset filter base for hood clearance then a 3/4" spacer to raise the filter base off the carburetor. I am hoping to get some of my questions rather than during the actual installation.
Thanks in advance for your help.
gene68ss

Post the specs on you cam and maybe someone who has run the same or similar has some first hand experience with it and vacuum assisted power brakes.

Sorry, can't help with the little vs big booster, but just guessing, the bigger one would probably be more effective. You could always get shorter VCs unless you need tall to cover a shaft system. Of course your answer to the question above may make you decide to go to a manual brake system, which makes the booster question moot.

You could check the clearance on your drop spindles pretty easily. Bolt a hub and a steering arm onto the new spindle, bolt the wheel to it and have a look see. You can do this on the bench.

The vac port pass side front baseplate on your 650 DP is a good place to check engine vacuum. If you have a port in the front metering block pass side it shouldn't show vacuum at idle, only after the throttle blades are opened. Your carb should have a large port on the rear of the baseplate which is a good source for vacuum to the booster.

You could also use a 3" tall element in your filter housing to gain an inch of clearance if you need to.