Holley 4160C

what do you mean, 'what kind of sec'? Jets? Type?

what size carb?

whats the rest of your motor look like?


Are you getting the drift that your questions are vague?

Vacuum secondary Holley carbs have that round spring housing on the passenger rear side of the carb. Find your carb at their web site:

http://www.holley.com/categories.asp?division=Holley

Their tech support is very helpful also.

Look on the choke horn and get the list # from it. Post that here and we can tell you what you've got. A 4160 can be anything from a 390 cfm to an 850. That's just the basic model # for the carb. ( 4150, 4160,4180, 4010 are 4 bbl carbs-- 2300 and such are 2 bbl's)

List 80457 is a stock replacement 600 cfm vacuum secondary 4 bbl carb for Fords. Bolt it on, adjust your timing to about 12 degrees BTDC, screw the idle mixture screws on either side of the main metering block all the way in ( just til they bottom out, do NOT force them), unscrew each 1-1/2 full turns. Adjust the idle speed screw til the throttle shaft is closed, then screw it back in till the throttle just barely opens. Crank the motor up. you want it to idle at about 600-700 rpms ( in gear if an automatic) to get this setting try the idle mixture screws. If those don't get it, then open the idle speed screw til it does. If, after doing this, if you'll try the idle mixture screws again and there's no response from them, you have the idle speed screw down too far and the throttle blades open to the point where the carb's in the transition circuit. Back off and start over. If the idle's too slow, advance the timing a bit (12+ degrees BTDC) too fast and you'll need to retard it some (-12degrees BTDC) Once you have the idle set, it's time to play with the secondary spring. I can tell you right now, that with the spring that's in there, the secondaries will not open till the motor's in a hard pull at around 4000-5000 rpms. Buy a secondary spring assortment pack. In there will be 7 different springs. Usually on a 289-302 the "purple" spring will let the motor pull the secondaries open about a second after you nail the throttle. When it does, you can "feel" them come on. With the lightest spring they'll come open almost instantly.