is this holley a marine version?? it has 4779-6 on the air horn and has the j tubes

I don't believe it is an official "marine" carb. Someone may have added the "J" tubes (not available from Holley separately), but throttle shaft seals are included on marine versions as well.

you have a automotive carb. model 4150 750 cfm.with 71 main jets 80 secondary jet or plate,primary powervalve65,i would not use on a boat hope this helps.

it was on ebay as a marine carb, I got out bid