I,m slowly but surely putting the GTX back together and have got some great help on here.I,m getting ahead of myself,but since I,m waiting for parts to finish putting the top end back together on the 440 I have question about the carb. I have the original Carter AVS,in fact I think it was on there when I took the car off the road 10 yrs ago.I also have a Holley 750 performance series carb that I bought years ago with the intent of putting on the car.Since the 440 is staying stock other than the six pack spec cam,which carb would work best? I,m wondering if the 750 would be too much for the stock 440.And if I,m keeping the AVS,are rebuild kits still available?

As a 53 year old motorhead since 14 years oil I believe that if you want to just drive the car and aren't worried about every tenth of et's the AVS is an awesome choice.

Holley

Carter is good carb. If you arw building a warmed over or high peeformance street motor, they work great, and they are very easy to work on. I've done a bunch of them and the first one I did I had zero experience with carbs. Even if I knew how to work on holley carbs, I'd still use a carter or edelbrock on warmed over or stock engine just cause they are so cheap, simple and work so well

And yes there are rebuild kits.

the avs will perform as well as any 750-800 holley. the issue is the emissions built into the carb. there are idle mixture screws under some lead plugs at the base of the carb that will need to be uncovered for mixture adjustments. the idle jet is probably too small and can be easily enlarged. you can end up with a trouble free carb that will perform as well as any comparable holley.

I agree, nothing wrong with the stock AVS at all. What year is your car?

three things that take no imagination

SBC

Holley Carb

Ford 9"

look at any generic street rod.

Put me down as another vote for Carter AVS .

Greg

Its a 69 GTX...440 auto with ac.Mostly original.It had a repaint many years ago and its a nice driver. I have a feeling I cant go wrong with which ever carb I go with!

All (OE '68-'71) AVS's are lean from Ma trying to meet the discombobulated Federal emission standards of the day (Furd/Chebby too). convert it to use Eddy Performer 2 step metering rods/jets. Fill the domed metering rod caps with JBweld then cover it with scotch tape then turn it over & let it set for 2 days so the mud will settle & harden out level then pull the scotch tape. Start with a rod/jet combo several tho larger (richer) than (AVS) stock on the power/cruise steps & go from there. Purchase a strip kit with rods/jets close to the dia's your AVS has

The avs will be fine. The holley will be fine. Which do you feel most comfortable working on? Sounds like the car is mostly stockish so the avs woukd look more "correct" and you likely have the oem fuel line already.

Without a doubt...


Leave the 'MP' fer someone else...

What is the primary throttle blade bore size of the AVS?
1-11/16 = 750 cfm. so if same CFM, which one is in better condition?
I'd check the throttle shafts for wear, it could make the decision easier if one is really sloppy. If same CFM and condition, it would come down to preference.

If you are not set on 100% stock and have a little $ to spend why not try the Street Demon carb? Youd have a brand new carb and its intended target is high perf street driven vehicles.

look at the front of the carb and see if the numbers 4640s are stamped on it. i have a '69 r/t 440 auto with it's original 4618s avs. what i've done is change out the leather accelerator pump plunger for newer viton edelbrock. i use the stock .101 tall primary jets with a 16-575 metering rod (.065/.060/.052 three step. these are no longer available but an edelbrock .065/.052 will work). stock .095 jets in the back will work with a stock engine. i've unplugged the mixture screws at the base of the carb and they're backed out 3 1/2 turns. the only "tricky" part is the idle jet. it's the small brass tube that hangs out the bottom of the primary cluster. these are .031" from the factory, too small. i've tried several sizes from .031" to .040". i've settled on .033" which is a tad lean (manual transmission carbs used .035" which is about right). i use a .028" afb squirter i modified to fit the avs (simple to do) and have the pump shot rod in the top hole. this carb starts, drives and performs quit well with the near stock engine (summit 6401 cam; idles smooth, very good low end). keeping the avs lets retain all the stock linkage and choke assembly and you give absolutely nothing up in performance to a comparable holley.

it is a 4640s. I still have the metal tag that mounts on the base of the carb with 4640s stamped on it. The car ran decent when it had the Carter on it way back when,just didnt have a lot of guts for a Big block.I did narrow things down to the upper end of the motor and had the heads rebuilt and installed the Comp cam,so I dont thing the Carter was a problem.While it was apart,thats when I bought the Holley,just never used it.

A 750 AVS was a stock carb on performance 440's. Keep it, cheap, reliable, makes good power, easy to tune. While there not as tunes me as a Holley due to the multiple tuning points a Holley "can" have, the Carter will work very well.

Many say Holley but fail to mention which one of the many or which manufacturer or modifier of Holley to go with. Since there hundreds to pick from and then modify yet again, it should prove to be an outstanding carb. But it doesn't.

The abilty to tune a carb is key. No matter what carb you have on top.

Chuck, I'd say rebuild the AVS and start there. If you don't like it, try the Carter.

I switched my 1967 2bbl 383 Satellite over to an AVS 8 years ago, never regretted it for a moment. I'm not a performance guru, but like to have some power. Easy to rebuild, easy to drive, no fuss no muss.

You've got the tag, so for a kit just call Larry Isgro Carburetors, he is on Long Island unless he retired, but I've been getting my rebuild kits from him since 2001. http://www.yelp.com/biz/larry-isgro-carburetors-wantagh

Best,
- Art

LOL

The Holley 4150 is an engine fire waiting to happen

If you have the Carter 4640S use it

Art,thanks for the info and the link for the rebuild kits. On a side note,how do you like those Alfas? I was looking at a local Alfa Spider Veloce for sale..looks like a nice clean car that needs a little TLC! Something different from the Mopars,but I,m open to anything on wheels that is fun to drive.

Other then the carters loving to cut out in sharp bends unless you really work them a carter AVS is fine . use 110 needle and seats and you can keep the air valve tension so it snaps back 2.5 tuns from base . Frankly I like the Holleys as I'm totally used to working on them and they can be tuned to perfection. Myself if its a 3310 vac sec run 70 jets frt 76-77 rear and the heavier yellow spring If its a dbl pumper run 71 Frt and 77-80s rear. Whatever you do get it back on the road and blow out the dust your neighbors may not like it but who the hell cares!

I do love them. Yes for sure Alfa's are super fun to drive, manual shift and to get the power out you rev high, so the experience is just great. Handling and balance are excellent. Parts and advice are plentiful (surf around, look in their classifieds and even ask if anyone knows about your Spider on www.alfabb.com) and not expensive. Upgrades are also plentiful. They do take extra care though, like things have to be repaired before they fail..
- My '82 has the fantastic V6 and been very reliable.
- The '94 has the bigger V6 with 24valves, but has electrical issues that are hard to really get completely sorted out. Modern stuff gets complicated. Bummer.

But don't let a '94 sedan scare you away from a nice used Spider! They would be a great start, Good luck!
- Art

carter for longetiviy. Holley is finicky sometimes

i think either carb is fine, but im always surprised at how much flack holleys get for leaking. i have holleys on all my junk and none of them leak. they all run good and are trouble free. now, i have worked on some that had issues when no fuel filter was used and there was a bunch of junk in the tank

I haven't had much problems with holleys leaking. Usually the accelerator diaphragm is loose or cracked will cause the leaks. Or maybe they are referring to the needle/seat adjustment? The gaskets here can stick and tear when adjusting float level. I usually put a coat of chap-stick on the gaskets to keep them from sticking and tearing.
The old Holleys with the accelerator pump check ball can loose function if the carb gets dirty and the check ball no longer seals. The rubber check valve on the newer holleys seems to work/seal better. The newer holleys also have the back-fire check ball to protect the power valve.

The carter doesn't use diaphragms for the power valve and accelerator pump so they don't have these issues. The needle/seat is not externally adjustable, so no point to leak, but harder to adjust float level.

Thanks for all the help and advice! I have a feeling that I should be good with either carb. I think what I,ll do is,when its ready to fire up,I,ll put the Carter back on and use that until the car is up and running and all the bugs are worked out. Then as time permits,I,ll try the Holley and see if there is much of a change. I,m not looking for the last 10th of a second or anything like that,but since I have the Holley and probably will keep it,I might as well monkey around with it. Back in the day when I was constantly buying and selling Cudas and Roadrunners and all the other Mopars,it was just normal to pull the original carb and put a Holley on. The GTX is the only one I can recall that I kept the original carb on! It has served me well.

If such is the case, your float levelis low. Raise it up and it won't cut out.

I vote AVS. OE 750 or Edel. 800.

Too high or too low you do not see many cornor carvers using a Carter for the float reason alone. I have over 5 AVS carters and a AFB and there is a bend that they really like to start to die out The Holley and Rochester Q jet don't just the carters I have finally decided to just run the Holleys they are reliable and they don'y care about rough roads or real sharp bends By the way did work out a AVS solution by running the carter as dual inlet but too much involved for the regular car guy

Same here. I have had the same 750 Holley DP on my sons Dart since 1997 and it has never leaked and works flawless. The 850 on my 63 has been on it since 2006 and is the same with never a leak and works great. Carters and Eddy carbs are good too as I have no problem using either. I just like Holley's better on my muscle cars. Ron

You said the engine is basically stock and the carb was the correct one for your engine? Is it in good shape? If so...

Factory engineers spent hundreds of man hours calibrating that carb to work on the engine combination you have. If there's nothing wrong with it, I dare say you'd never get the Holley's cold start, warmup, part throttle cruise, and fuel mileage anywhere near as close as the AVS already is. Yeah, the Holley "might" make a few more ponies at WOT but honestly, how much time do you really spend there?

Trouble is when you raise up the float level it will cut out under hard braking!