The Holley carb on my boat is like that. When going about getting a rebuild kit for it, I had to use the number on the metering block. What would be the point in that, removing the choke horn? Clearance issues?
Also, I had been told the carb was an 850. The guy I was talking to about the kit says the number I gave him, 4776, reveals that its a 750. Is that correct?
A 4776 is a 600 double pumper, but as I mentioned before if it's not all original the metering block could have been changed. One way to tell is to measure the venturis and the throttle bores!. Pri venturi= 1 1/4" Sec Venturi= 1 5/16". Pri throttle bore= 1 9/16" Sec throttle bore= 1 9/16". Milling the choke horn increases air flow, also makes it easier to access the squiters!...