TylerSteez

iTrader: (3)

the engine is a 383 stroker, xe282hr cam, 195cc aluminum dart copy heads, and an RPM air gap intake. 5.5PSI fuel pressure. Timing at 16 degree initial and 36 degrees all in at 2800rpm. Advance is off ported vac because I can never get consistent idle quality with it on full manifold vac. transmission is a reverse manual 700r4 with a 2500 stall matched to the cam. rear end is the stock 9 bolt 2.77 but I'm about to order a 9" 3.70. All Carb tuning was done with an AFR gauge.

I originally had an Edelbrock 1407 750cfm carb on the car. I must have read endless forum posts along with the instruction booklet. No matter what I did to it, it would constantly need something tweaked on it a week later. It had a massive lean spike right off idle if you got on it. no matter the accelerator pump arm position, transfer slot exposure, squirter. This spike created a bog that would either shut the car off or just fall flat until the fuel caught up. Carb was clean as a whistle inside, also added a phenolic spacer to prevent heat soak (even with an airgap intake). The idle would also change on me week to week. Id set it around 850rpm and then two weeks later it would be idling at 700rpm. Constant fiddling. I ruled out any possible vacuum leak, even pulling the intake manifold and resealing it with new gaskets just incase. I don't want to necessarily blame the carb or edelbrocks in general because I'm not a carb guru and they work great for other engines but something just was not adding up and I was tired of messing with it.

The final nail in the coffin for me was that I thought I finally got it where it was happy, it was running decent as long as I didn't snap from idle to WOT, great cold starts, no issues. Then I randomly had to move my car this past wednesday and out of nowhere it would bog and stutter any time I gave it any gas. I parked the car and immediately went to order a different carb.

I was going to do a traditional Holley but a few things put me off. My car is an automatic street car so a 750 double pumper didn't seem ideal. I then started looking at their vacuum secondaries. Initially narrowed it down to a classic holley 750 with an electric choke/vac secondaries or a Brawler for New England winters but then also saw the Demon Carbs. I liked the phenolic bowl and simplicity of it. Did some research and saw a lot of positive reviews from the Mopar community. Figured it would be a great simple carb that will let me finally enjoy the car.

I ordered it and a tuning kit and it arrived two days later. I spent the weekend dialing it in and I couldn't be happier at the moment. The idle was immediately more stable and it was repeatable every time I turned the car off and on. The AFR's with the stock metering rods was a tiny bit rich so I swapped them out for the next biggest size. My engine makes a steady 12lbs of vacuum at idle so the stock 6lb step up springs were fine. had a lean spike off idle so I put the accelerator pump arm in the top hole and bent the arm to spec as described in the instructions and that went away. Got the idle AFR around 14 and running super smooth.

I then took it for a test drive and the AFR's were very consistently 12-14 depending on where the throttle was. When the goggle door flap opens and the secondaries open up it shocked me how hard it pulled. The car felt like it was on nitrous. I never felt that with the edelbrock. part throttle cruising and behavior with just the primaries is smooth as well. no weird stumbles, bogs, or weird idle drops. The edelbrock had me afraid to take it out too far from my shop incase it acted weird and broke down on me, this carb gives me fuel injection-like reliability confidence with the car.