I don't know much about dyno's and such as that, Tech or maybe some of the others more versed may speak up. I have been running dual quads on SBC's and BBC's for quite a few years. Not once have a seen a seat of the pants drop in horsepower going with two 4's, and I from my own experiance "think" that I do feel an increase in power. I do run Edelbrock Carbs 600's on the BBC and 500's on the SBC. These carbs are vacuum secondary carbs and draw what the need, in the two sets I am running now the seem to perform very well.

I am not a fan however of tunnel rams on the street. The are meant to perform at higher RPM's and I just never had any luck with there streetablity.

Roland