ok so maybe not the biggest but it is a 750 holley double pumper and the fuel ratio is primary 30cc secondary 50cc that is 80 cc's of gas at wide open throttle.....wtf am i supposed to do with this lol guy sold it to me rebuilt all cleaned up really nice stuck it on my buddies 350 just to drive his truck around until he gets one and we get on had to set the floats and stuff get idling and then we started playing with it. He has a new motor we matted it wide open throttle and the truck goes WAHHHHHHHHHHhhhhhhhhhhh...hh....h...h....dies lol we are like uh did u just lose compression cause none of what just happened made sense to us pulled a spark plug out gas was everywhere......spark plugs fouled everything so my question is should i sell it, jet it down, or what?

 

what is the truck going to be used for. everyday use, street/ strip. i dont know alot about carbs but that sounds awfully big. i think 650 gets the job done.

 

dont even mess with trying to re-jet it... just sells it and get a 650 thats not a double pumper... one of the avengers series would make a good one

 

The 750dp is way to big for a stock 350. When my 350 was stock I was running a holley600 and it ran great. After I changed the intake manifold, milled the heads, rebuilt it with hyp flat tops, and added a slightly more aggressive cam is when I went to a 650dp with 50cc primary and 30cc secondary pumps. Anything more than that would be overkill for my setup.

You will have to re-jet it if anything. You are getting way to much fuel. I would save it or sell it and buy a 600-650 non double pump with vacuum secondary's.

That carb is far from the biggest, Dominators and RS demons dwarf the holley 750.

 

man i thought that this thread was going to be about these when i clicke on it

 

It's not that it's "TOO BIG"....it's too rich. Lean out the jetting and set the timing first. Then when it runs decent you can tune the squirters and the pump cams.


That said....750 is a pretty healthy carb for a stock 350 on the street, but it's not impossible to make it run. I had a 750 dp on my slightly modified 305 and it ran nearly as good as the OEM style Q-Jet.

Tune, tune tune.

 

Oversized carbs tend to run lean, not rich. If it's choking the engine with fuel, there's something wrong besides jetting.

A 750 DP is a bit big for a stock 350, but it can be made to work, at the expense of mileage if you're on and off the throttle all the time.

 

yea but it wasnt a stock 350 it was bored 60 over however. The carb came off a drag racing 454 big block. I wanted it cause with my setup it wouldve worked great. My setup was 3000 stall, stock 350 block with the stock 083 heads milled 20 down new valves springs retainers making them good to 550 lift with screw in studs with my self porting and i went BIG, converting from tpi to carb with a performer intake ported with a highrise adapter for more height, and the 750 double pumper, being pushed by a th350 and 373 gears. Engine had stock 4inch new pistons rod and same crank shooting for a high rapping motor. but ill figure something out and holy hell those carburetors in your pics were big lol.

 

haha project89, those were exactly the ones i thought that were going to be talked about too when i clicked the thread!