Paging Lars and other carb experts, Holley 4779 base tune for a 406
 

Guys, I rebuilt an old 4779 Holley to possibly use on my 406 sbc for the '71 vette. Anyway, it's a early 4779, no dash anything and the date code is 164. The factory jetting was 75 pri, 76 sec, and an 8.5 power valve. Anyway, it didn't come with front jets and had 75's in the rear. Had a 6.5 power valve in it. I put in a Quick Fuel complete rebuild kit that came with a new 4-door 6.5 power valve. I also put in 70 jets for the primary, 80's for the secondaries. It's got brown cams for both pumps, a 28 sprayer for the primary pump and a 37 sprayer for the secondaries.

I based the jetting off of the later 4779's as anything past the first gen 4779 had 70/80 jets and a 6.5 power valve.

Is this a decent place to start? Pump setup look O.K.? Also, it doesn't have four-corner idle. This shouldn't be an issue, right? Choke was also removed. I'm assuming for a summer car this won't be a problem?

Anyway, thanks much guys!

Here's my general advise on that carb (and any Holley carb):

Set it up to the stock jetting for the carb number and tune from there. Don't be afraid to jet it too rich - it's when you go lean that you have tuning and drivability issues. Keep the primary/secondary jetting split at 8 jet sizes if the secondary side does not have a PV. If you run into any hesitation issues, bump the squirter size up 4 sizes, and don't hesitate to bump jetting up 2 sizes from the stock setting. Be sure to balance the primary and secondary idle speed screws so you do not expose more than .020" of the primary transition slot at idle.

Lars

Thanks mucho Lars. I'll give it a shot! Also, just ran the numbers and that carb was built in 1971. Might just have to put it on the '71 vette!