Al,The best streetable carb for a tunnel ram is a Holley 390cfm carb 0-8007
These are vacuum secondary carbs. they are in 99% of the time just bolt on and go!
Did you block the constant feed discharge hole that feeds from the transfer slot and drill the air bleeds to the same as the primary bleeds when you made it into a 4 corner idle ?? That might have caused the secondary to be rich if u didn't. Really cool you made them into vacume carbs.I've got dual 450s sideways on a weiand ram 406 sbc. I converted them to 4 corner idle to get the plugs to even out their idle color. When the carbs were inline they still had uneven plug colors (sec side was rich), the pattern was just 3478 rich instead of 1357. The motor ran the same either way. I've also converted them to vac sec to slow down the initial opening and get a crisper launch. I probably should have got the 600s (Summit combo) but when I ordered it I thought the 450s were vac sec. All the bosses are there, you just have to finish drilling and tapping them. I robbed the secondary shafts and diaphragms from a pair of 3310s. They work good now but it took a lot. Lucky I enjoy tinkering!