The fires were from people insisting on opening up three times the carburetion the engine needed, suddenly, causing a drastic lean condition and a horrendous backfire that blew fuel out of the float bowl vents all over a hot engine. Since those same guys were smarter than all the GM engineers and also used steel tubing headers instead of exhaust manifolds, a fire was inevitable. These aren't rumors- - - -I grew up around a bunch of idiots in the 1960's who needed to be designing cars for GM- - - - -every one of them was a legend in his own mind where fuel systems were concerned! Good luck with your project!
Jerry
Edit: If you insist on using 2G carbs, jet the outer ones WAY rich. They won't flood, and if you suddenly open up two small-jetted carbs you'll create the ultra-lean conditions I've described. Jets can only respond to air velocity through the venturis, and dumping the throttle plates open quickly drops the venturi velocity so low that there's no vacuum to draw fuel from the jets. You get a super-lean condition and a backfire that makes a 12 gauge shotgun sound quiet.
Jerry
Last edited by Hotrod Lincoln; 04/29/2014 7:45 PM.
