Carbking, Holley 2300's and 4150's leak if butchered by ham fisted mechanics.You certainly have a large shop and way more experience than I do, but I rebuild and sell about 50 Holley modular carbs a year and never had complaints about leaking fuel.I buy carb cores on Ebay and at local swap meets, 90 percent of those carbs have jetting that's been changed way off specification ,and improperly adjusted floats.Since these type Holleys are the most popular for performance use,have external adjustable floats and readily available jets and such,many well meaning tuners feel that's a license to turn every screw and re jet a perfectly good carburetor.Guys reef down on the bowl screws until the main body warps trying to stop leaks from improperly installed gaskets, wrench power valves until they rupture,drill out air bleeds, then blame the carb.It's just amazing the damage they do.I mill the main body true again,put in Holley brand parts, return the carb to stock specs ,good as new.
Holley's, just like AfB's or for that matter most any carb, will work great out of the box if used for an engine close to the original application it's designed for.
The Holley 2300 I mounted on a modified stock intake on a 261 cube Chevy 6 cylinder carburetes excellent, an amazing up grade from the stock 1bbl Rochester,all that for a $19 Holley kit and a 10 buck swap meet carb core.The Holley is originally off a 266 cube IHC V-8, flows about 220 CFM as rated like a 4bbl.
I really like AFB's but when using the carbs off spec like on my modifified 6 cylinder,it required a lot of tuning with parts I couldn't easily find for reasonable money.
Carbs are just like women,treat em nice,it's wonderful,treat em crude,it's hell
