Spring loaded needles and seats

I have Holley 4160. I want to change the needles and seats to the spring loaded type, but I am intimidated by carbs. Is this an easy thing to do?

Karl

 

Yes. Holleys are easy. It can even be done with the carburetor still on the engine. Raise the bowl vents too.

 

For my 4 BBL, I connected both vent tubes with fuel hose & a Tee, then ran an overflow slosh tube from the tee.

gj

 

I have looked, bout cant seem to find what the float should be set at . Do you guys invoke the force? Do you use the site bowl or some measurement off the mating surface?

Karl

 

My Chilton's only shows an Autolite 4 BBL - 3/4" up to 1975.
Sorry, my Holley book is out on loan.
You should be able to eyeball a fill line on the inside of the bowl(s) from old fuel.
Try contacting a Holley retailer and asking them for the measurement or to measure the float spacing tool.
If you hill climb or bounce around alot, set the floats to the low side & set up your slosh tubes on the bowl vents.
Nothing beats a Carter YF SB (on my 232) for hill climbing and steady idle. I ran a dual port intake & a Holley 390 Comp. on my 232 for a very short time. For off-road conditions, it was terrible.
There used to be a placed in CA that would off-road proof your carb. The fees could exceed the price of the Holley, but the end result was offroad race proofed.

gj

 

I have a holley 390 on my 258. I had it "offroad proofed" by a local holley guru. works great. From what I understand one of the things he did was put in the springload stuff. Also be sure to have a check valve put in to protect the power valve, or one back fire will blow it.