Just thought I'd throw this info out there...Now, I know not a lot of you run demon carbs and even less have the older BG-made units...I use a 2007-vintage 850 speed demon/mech secondary carb on my .040-over 440/9.5ish compression/edelbrock rpm heads and intake/comp XE 274 cam (230°@.050)/1-7/8 TTIs to 3" exhaust w/ultraflow mufflers/2400 stall/3.73 gears/28" rear tires. Most of us know that BG rated their carbs wet and thus they flow higher than the ratings..stock jetting was 85/92 w/ 6.5 PV. Friends would say "wow that seems like a ton of jet" "isn't that carb a little big?" "my 454 uses 80 and 86 blah blah" So I've been doing lots of tuning & experimenting with jet sizes on this thing lately(fun stuff) and I've discovered my warmed-but-not-too-wild combo loves even more jet than stock..I felt the power loss even at 2 steps down, right now it's running harder than ever all through the rpm band with 86/94, with one extra step of spread from factory..I stopped there because I don't have any bigger ones in the drawer. Now I must mention this is all butt-dyno, no a/f meter or 1/4 mile slips yet so I'm not trying to get too detailed, just sticking with what runs best. I know you don't really notice a few HP here and there so the gains must be substantial as there's no doubt to the increased performance. ANYWAY sorry for the long winding post my point was, demons seem to respond a little different than my holleys did even though they're the same basic design..A friend has a 10-second '66 Belvy with a built 440, more cam/head/butt-kickin' than mine yet he likes his 850 holley DP jetted at 78 and 86..every combo definitely has different needs
