Hey guys, just curious... are there any kits out there for different style boosters for a 4150 (4777 specifically) style Holley? How are the boosters removed/installed? I've looked at Summit and Holley's website, and can only find kits for the 4500 carbs (Dominators).

I've heard that it may be good to change from the original straight-leg boosters to a set of down-leg boosters like my 750 VS has, or to annular boosters. What kind of change would I see from changing the boosters? Power? Drivebility?

 

call the carb shop in california and talk to them, not something you can swap out at home anyways.

 

Why can't they be changed? They don't appear to be part of the main body casting...?

 

it's probabily more cost effective to change the main body to a Holley HP or a ProForm main body and work from there.
For $100(US) You'll pick up air flow, metering strength and air bleed tunability all at once. You'll eat that up easily paying a carb specialist to modify/change your boosters and dial in the new fuel curve.

 

Why does a pro have to change the boosters? Thats what I don't understand... why isn't this something I can do myself?

I don't want a HP or ProForm body, because they have no choke. This car is still street driven, so I want to keep whatever little bit of 'manners' it has left lol.

 

You can't do it yourself. They look like they just slide in there but they don't. You need a shop that does carbs to change them out.

 

quick fuel charges $40 to change boosters. I am getting mine done from the straight to downleg next week. mine is in a proform main body but should be the same price if you take off the choke plate when you send it to them. there is a special tool to do it. if you want mor einfo pm me. they told me unless you are making alot of power than stick with the downleg.