holley help

i have a 750 double pumper a 4779 i believe. It is too small for the engine. I was wondering instead of buying an 800 or 850 or 950 carb, can i swap the main body and use the bowls and metering plates and jets on the larger main body?      

Why do you believe it is too small for your engine what is it doing.  
Professional hi-performance engine builder

Horsepower sells Engines and torque wins races.

bog/hesitation/stumble on acceleration. Went to several local speed shops and racers at the drag strip  and asked questions. they all said too small of a carb, should be a minimum 830.  

bog/hesitation/stumble on acceleration. Went to several local speed shops and racers at the drag strip  and asked questions. they all said too small of a carb, should be a minimum 830. even the holley website recommends an 830 as a minimum.  

what is the specs on your engine.
It may just need to be tuned in better with larger jets,shooters,ect.  
Professional hi-performance engine builder

Horsepower sells Engines and torque wins races.

bog/hesitation/stumble on acceleration   is the accelerator pump  too small leaking or misadjusted,   the accelerator pump shooter too small or the check valve under the screw not holding when you foot is taken off the throttle... so it sucks in air... this limits the amount of fuel it can put out when you tromp on the gas..

if the accelerator pump cam is wrong for your set up,   there are 5 or 6 different ones... some with 2 different screw positions some with 3...

you might buy a Holley trick Kit.. for your carb... as different shooters and pump cams come in it..

there is also a chance that the idle feed restrictions are too small...

you have to understand...  at idle... the motor runs off the round idle mixture holes below the throttle plate... off idle and until the airflow over the boosters is fast enough to pull fuel over.. it has to run on the idle transition circuit.. and the accelerator pump shot.. but the pump shot only lasts as long as the throttle is moving..

if  you have a large motor.. with a large volume intake manifold.. you will need more accelerator pump shot to prevent the engine going lean...   earlier pump cam adjustment..   larger shooter..  perhaps switching to a 50cc pump kit..    the 50 cc  kit also uses different pump cams..    by the way... its 50cc with 10 strokes..   the normal one is 30cc.. for 10 pumps...


larger carbs have larger idle feed restrictors.. and are properly tuned for large motors with massive intake plenum volumes..