Help need suggestions & advice

I have been expierncing a huge issue that has about drove me insane and has me very close to giving up on my 360 magnum. I have a 300hp crate 360 magnum in my 91 short bed half ton 4x4 truck, the truck has a non lock up A-518 transmission, I had to buy a lokar throttle valve cable to hook up to the transmission so the transmission would operate correctly.
I have a 650cfm edelbrock avs carburetor on top of a dual plane edelbrock rpm air-gap intake. I purchased a throttle bracket made by AR engineering for the carbureted 360 magnums.
The problem i am having is this throttle valve cable going to my transmission is wrecking havok on the edelbrock carburetors i have tried to run, what happens is the bore that the throttle shaft rides in wears down and i get a fat vaccum leak at the throttle shaft. It happened to a 1405 edelbrock carb that i purchased brand new, so i bought another edelbrock the avs i currently have, and it happened to the avs within 2 months. So i spend 150 bucks sending the avs off to a carburetor shop in new york to have the baseplate bushed with teflon bushings. I got the avs back put it on and my engine idle still varies and the throttle shafts still leak fuel if you pump the gas pedal a few times with the engine off and it just doesnt sound like its running right, I'm starting to wonder if this carburetor shop even bushed the base plate, and i still have real bad throttle shaft play up and down and side to side.
So here is my question, does a carburetor that can handle a throttle valve cable even excsist? I am so tired of fighting these vaccum leaks and i am tired of dropping 300 to 400 dollars down for a new carb every other month. What can i do here? Do i need to just opt for a 5 speed manual and get rid of this A-518 so that i dont have a throttle valve cable?
I am willing to buy one more carburetor brand new and see if the throttle shafts can remain vaccum leak free, The carburetor i have been looking at the most is a quickfuel ss series 680cfm vaccum secondary carb, it has a 4 corner idle, changeable air bleeds, changeable idle feed restrictions and it has teflon coated throttle shafts with teflon shaft bearings. The price tag of this carburetor is 527.00. What would you do? And what do i need to do? Because this is so frustrating i feel like just throwing a for sale sighn in the window and passing this headache on to somone else.

It's hard to believe it's the carbs fault, since it's happening so fast. I assume the shaft wear is on the firewall side of the pivot. Since the Lokar mounts to the lower side, I have to believe you have a bad cable (extremely tight) or it's adjusted to tight and doesn't have the full range of movement.

I'd unhook the Lokar, then open the throttle all the way, and manually pull out the cable and make sure it will come all the way out to the current mounting point.

I've done that, the lokar cable comes all the way out. Is there anything i can do down at the transmission end? My lokar cable is new, and i have taken the cable off and manually pulled it up and down and its smooth

I can't believe it's a carb issue either. You could try a Holley or another brand, but I'm betting you will have the same issues. Something has to be pulling continuously on the shaft to make those bushings go bad. Got any pics?

If you can pull on the cable and it's smooth and easy, it might be the material the edelbrocks are made from. You could take that carb to a machine shop, and have bronze bushings put in. Maybe the material would be more durable.

i sent the carburetor off to have teflon bushings installed, paid 150 bucks all together and i think the guy screwed me because the shafts are still leaking. He siad he would use teflon. So i dont know what to do. The cable when not hooked up to anything is smooth and operates freely. But when i have it hooked up to the transmission it is a little stiff to pull it. Is there anything on the valve body of the transmission that could cause it to be tough to pull the lever on the tranny?

I mean it pulls the lever on the transmission but it feels a little hard to pull it. And i think that is what is causing this. My throttle valve cable and accelerator cable are both new and my throttle bracket is brand new made for carburated magnum engines by AR engineering. So i really believe the problem is down at the transmission where my throttle valve cable goes too.

I can pull on the throttle valve cable when its not hooked up at the transmission and it's smooth and easy, but when i hook it up at the transmission and go to pull on it it's a little hard to pull, takes some torque to pull it all the way up.

Since i hate trannies that shift themselves anyway, i would put a manual valve body in it.

This could be from an over powerfull return spring as well.

it's not the return spring. I put a brand new return spring down at the transmission and at the carburetor and they are soft return springs. I had a stiff return spring at the carburetor with my first edelbrock and I bought two brand new ones that were a lot softer to put at the carburetor and at the transmission.
I have covered all areas when it comes to this issue. New return springs, new accelerator cable, new throttle valve cable new throttle cable bracket. All I can think of is that the tension from the throttle valve cable going to the transmission is just too much for the edelbrock's aluminum structure to handle.
That's why I keep asking, is there anything on the transmission I can look at or lossen up to make the throttle valve cable not as hard for the carburetor to operate?

so no one else has had this issue or heard of this issue? I'm surprised there has not been a lot more discussion on this very topic. Everytime I see someone posting about having trouble tuning an edelbrock I tell them to check there throttle shafts for vaccumm leaks and 80 percent of the time that's what it turns out to be.
My edelbrock avs carb had sloppy loose throttle shafts right out of the box brand new. So it's possible the edelbrock carbs just cant handle having a throttle valve cable, But I am still worried it might be something in the transmissions valve body making the throttle valve cable harder to operate.

Every time I've seen throttle shafts wear out prematurely it's been too much return spring that caused it.

Well my retun springs are not too stiff, they are accually pretty soft. I know its the throttle valve cable causing the issue on mine. I have my throttle cable racket adjusted all the way up and it does make it a little easier to pull forward.
But i'm starting to think that the edelbrock carburetors aluminum body structure is just not strong enough to support a throttle valve cable period.
I could buy another brand new throttle valve cable, but this cable I have is not very old and it operates smoothly when its not hooked up to the transmission.

Edelbrock Tech Contact Information (USA):
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Main Office: 1-800-416-8628

Oh iv'e called edelbrock and they just say all they can do is send me another one lol, they dont even sell repacement throttle shafts. I'm still not 100 percent sure what i'm going to do, but i am leaning twords getting a quickfuel 680cfm vaccum secondary ss series carburetor that comes with teflon throttle shaft bushings and teflon throttle shaft bearings.
I sprayed some white lithium grease down at the transmission where the throttle valve cable goes and it seemed to help make it easier to pull forward. I am begining to think the edelbrock carbs just cant handle having a throttle valve cable hooked up to them.