i know a guy that ran a supercharged blow through setup on a 351w and he kept crushing floats. he now is setting up a twin turbo fi 351. this is in a maverick not a truck but the same principles apply. His carb setup ran pretty good but he always had little problems tuning it. If you dont use the right parts then your asking for problems.
you either have to run the nitrophyl floats, or fill the brass ones. Tuning a blow through carb properly requires a good bit of knowledge of the inner workings in the metering block of a holley.
Guys be carefull with with Demon. I run a supposed Demon BT. Right out of the box it will NOT run and tech support from BG is non-existent. After months of tuning with an LM1 data logger I have it finally running well. I have just about worn the bowl screws out changing jets,resizing the high speed air bleeds,resizing the Idle feed resrictors,opening up the PVCR (power valve channel restrictors) and had to make a BRPV. (boost referenced power valve)Unless you know alot about carburetors or intend to learn alot I recomend C&S or CSU More expensive but worth it. IMHO
Both of these companies specialize in blow thru carbs, know they're stuff and offer excellent technical support. You will NOT get that with BG (You have been warned)
As far as I know I am the only one on the site running a blow thru and believe me when I say there is steep learning curve. But, that said you can make HUGE HP with one. 2000+
cool.... i just wanted to feed my straight 6 a couple pounds so it wasnt such a pig...
what about retarding the spark?? someone told me to stick with the vac advance distributor.... i think the only other option is a electronic boost controller from from like msd or something