4412 Holleys

If not buying a off the shelf or stock racing legal carb you may need to know some points of up grading the 4412!  They do sell a larger needle and seat set for more flow supply if you have the need and be sure your lines and filters, including the carb nut is open enough even if you have to drill it out a bit rather than buying one! Check your fitting size also! I have had to drill and tap the threads back to pipe size to put a larger fitting in the line! They do make a circle track float that allows a more constant level while in the turn or wide open! Gasket hole sizes can be in need of larger holes for better flow at the top flow bars! Always good to have extra gaskets and needle and seat as well as the O-rings and washer gaskets for the float adjustments as they are prone to by-pass or leak when changing the level or thinking trash is the problem! A change in pressure will change float levels! A new pump or higher pounds with the use of a regulated system should be re checked at the carb! A higher float level can change the ease of draw-over and be the same as changing jet sizes up or down if float level is lowered! Not running a choke the engines are prone to cough when cold or at any lean point, this can blow the power- valve if not equipped with a pressure release system! I for one never run a power valve and just go up on the jets about five sizes to compensate! You never know it missing and gives top-end fuel to keep the engine from getting tight from regaining vacuum! It also cools the pistons down more when lifting and leaves more residual to bank on improving traction off the corner instead of lighting the tires when you should be moving with your foot on the floor! This also helps with the lean effect that causes an engine to run warmer than it should, cools the intake and exhaust or keeps it flowing in the pipe burn depending on which ever way you see it working for you! 83-86 jets are what I run with out the power valve! Check the number of oily threads on number three as to the need of jetting! You should have at least 3-4 wet threads that can be checked hot or cold or even next week, the oil should be there on a R45T plug! If it should run lean it will burn the tip off and start missing instead of running a head gasket, block or piston! Remember that the air is just as important to jetting as the fuel! A bra net is like 2 jet sizes when clean because it too changes the draw factors at the bowl level to the jets by pulling more fuel if air is restricted! Even the amount of oil placed on the K&N filter works the same as a restrictor! Keeping a extra clean net as well as a dirty one will give you quick adjustments by the changing off the bra when those temps start dropping off later into the evening or morn as the case may be when running late nights! Paper filters may be easier to deal with but not the way to go as to moisture swelling the fibers if ever getting damp! The same goes as to restriction and jetting! I do a bit more than the next guy and burn twice the pump gas fuel and need all the flow to be faster with cooler air and fuel until the plug fires, legally!