Edelbrock 1406 jetting for altitude

[Grand_Wag_85]

I’m rebuilding an old 1406 to go on the 77 401 and I’m curious what you guys have done for high elevation? I live above 10,oooFT so it’s kind of a must.

[fulsizjeep]

I may have told you this already... I had an AFB on my 401 from 2004 to 2011. The first couple of years I invested a lot of time to read up and try different springs, rods and jets. I never really got it to run like I wanted even at 7000 feet. At 13,000 it was usually a matter of grinding teeth and adjusting the manual choke to bump the idle up a little but not too much. Silly me for waiting so long to swap on a Holley with electric choke. I was being stubborn and lost, later to be delighted with the swap.

[Grand_Wag_85]

You probably have told me :p

Which Holley are you running?

[Stuka]

You can certainly make an AFB run at high altitude. But a holley style carb is more tunable for sure. Its just a lot more work. Engine Masters actually had an episode that compared tuning of each and the power they made.

For a Jeep, its hard to go wrong with a Truck Avenger.

[fulsizjeep]

You probably have told me :p

Which Holley are you running?

Truck Avenger 670. A 470 may be even better for most 360/401 engines.

[Grand_Wag_85]

I'm looking at the 670 TA's. Is 670CFM too much for an old 401?

Finally ID'd my current carb, it's an old Holley 600...albeit tired.

[Stuka]

I'm looking at the 670 TA's. Is 670CFM too much for an old 401?

Finally ID'd my current carb, it's an old Holley 600...albeit tired.

The TA carbs have vacuum secondaries that are adjustable. So it won't be way oversized or anything.

But there is a 470 also, although it is intended more for 6cyl engines. But it would certainly work on a 401, especially if you don't go much over 3500rpm. It may need to be jetted a bit richer.