About that Holley carb ...

Don't have much to add directly, but we ran a Holley 650 with vacuum secondaries on a 351W in a full size 2 door Bronco. (a little bigger engine) and it was plenty.

Unless you have a huge cam in that 305 a 500cfm carb would be adequate, and the 600 will be as big as you want to go. As for the floats? if you are going off-road or severe off-camber driving the center-hung carb will make you a LOT happier. Can you put the center hung bowls on the 600???

I was wondering about switching the bowls ... which would also mean switching to the dual fuel inlet setup . I'll see what will fit when the "new" carb arrives . As far as the cam , the mfr classes it as a "stage

3 RV cam" (Elgin E-922-P) , whatever that means . I think it's pretty close to what we used to call a "3/4 race cam" . Specs are .444 lift intake and .466 exhaust , with 214° and 224° duration @ .050 lift (288° and 298°) . Lobe separation is 112° . I don't think it's all that radical ... I expected a reasonably decent idle around 800-900 , but I can't get the quad to run right below about 1500 or so (haven't hooked up the new tach yet) . Idle speed screw is almost all the way in and the idle mix needles are making no difference at all . I just totally rebuilt that carb , everything is spot on the specs and I sealed the metering needle wells with JB weld . This carb has had a history of long cranking to start if it's been sitting more than a few hours , like the bowl is emptying while it sits . I'm just tired of trying to figure this one out , I usually have no problems with getting a quad to run well .

Put a good heat insulator between the carb and manifold to help prevent the bowls boiling dry on a hot shut-down (makng the engine over rich after a short shutdown - and slow to start after a long soak. The "stage 3 RV cam" WILL be lumpy below 1200RPM but unlike the "3/4 race" will be biased twards low end "grunt", not high RPM performance. Good from 2000 to 4600 RPM. The 922 runs from 2200 to

5400 RPM - more of the "3/4 race" grind. - close to the factory z28 cam of the late sixties. The 921 is basically the L82 cam. Whar CR are you running? Hopefully better than 9:1

Original C/R was 9:1 , we replaced the .080 dished pistons with .060 over flat tops . The machinist that did all the work figured that I should be right around 9.5 or a bit more . This guy is known regionally for his excellent motor work . The motor came with what are supposed to be the best flowing stock 305 heads , I forget which casting number (816 ?) they are . I did a little port matching on them to match the Edelbrock Performer intake manifold . As far as the carb , I did use the thick spacer supplied in the carb kit . The truck has done this from the day I drove it home . I thought the well plugs might be leaking from researching that problem , so I coated the bottom of all 4 with some JB Weld - the machine shop guy also suggested I do that just as a preventive measure . If it's leaking , it ain't from the plugs . I really wanted to run that original carb , nothing in the world sounds like that quadrajet moan when you dump the throttle , and IMO the balance between performance and economy is very hard to beat .

Oh, I should have said that was two different CAMs. First time was somthing called a 1/4 race CAM. Second rebuild was with an RV (long duration) CAM. The same carb worked great for both applications. Never felt like it was leaning out.