Chrysler 360 w/ W2 Econo Heads, Headers, 30.over

1wild&crazyguy said
You don't need a street avenger, that is last carb I would put on any motor with some real cam in it, been there done that w/770 on a 440 10.1 284* .538 lift
3200 converter/4.30 gear.

That's why I suggested it with the cam change. My suggestion wasn't to be taken piece by piece but as a package. The Avenger also has all the vacuum fittings he might ever need.

Thing had a lean idle circuit, kinda like a 600 vac sec.
I would set the blades right to the slot and it would idle for s***, needed drilling of the butterflys.
Instead I had it returned for an 830 chokless, WAY BETTER CARB!

The blades should be set with a "square" amount of transfer slot showing under the blades. In other words the height of the transfer slot showing under the blades should equal the milled width. This may well have been your problem. The newer Holley's have been known to have some milling/casting garbage floating around in them too. As with any part, it should be disassembled when recieved and gone thorough. You wouldn't believe the manufacturing crap I found in some of the most high-end parts.

Avengers are for stock to 'mild' engines with milage in mind hence the leaness out of the box.....

Well, it's the annular boosters that help the mileage out and help out idle/main transition. This is just what is needed when vacuum is low with a big cam. The jetting is 72/75 on the 770 model and 78/82 with a 4.5 PV and .040 squirter on the 870 model which is what you should have chose for your 440 anyway. Neither of those carbs would I call "Lean". Drilling holes shouldn't have been necessary either as the secondaries can be adjusted to add additional air as needed. Regardless, big cams are better off with a 4150 style dbl pumper, no doubt.

Wwwfora,

The Percy's "adjust-a-jet" metering blocks are handy, but not really worth it IMO. The Quick Fuel metering blocks are awesome, but are not for a begginer to play with and will not solve you problem. As I said before, the cam and ports are too big for your application. No amount of carb tuning is going to give you crisp off-idle performance with that cam, period. This is a very common problem and I see it lot with people saying "I want a 450hp 318 that gets 20 mpg and I need to drive it 20 miles to work every day." Well, without forced induction or nitrous, it's not going to happen. Then I get called a 318 hater, lol! :-D

Every build with a use in mind should be built from the ground up. The band-aid approach never works well. Since you do not want to do anything I suggested, all I can say is add a higher stall TC so the engine can rev into it's usable range and kiss whatever mileage you are getting goodbye.