Intermittent carburetor backfiring on both sides

All my text is gone yet again 3 times now. The catb is mostly clean at this point. It appears to be 2 different carbs melded together. The ID tells me that it should have a single bowl fuel connection but it has 2.

The secondary diaphragm needs replaced.

There's damage to the primary and secondary plates I'm guessing need cleaned of rust and repainted?

The 2 holes leading to the front and rear vacuum ports seem to be routed out a bit as do the 2 tiny holes right next to the bigger holes. I don't know what this might cause.

Then in the primary channel there are some strangely shaped metal pieces I suppose are blocking or partially blocking the flow? The one looks like it might have been minimally reduced at least in 1 place.

Take a look and let me know your thoughts.

I'd love to get an injecton setup but aftermarkets are crazy expensive. Could I get an top end from an LS or a VI or wouldn't it fit?

If people spend that kind of money adding an aftermarket setup why do they take them off? The whole 4bbl carb/injector setup seems odd to me.

Okay, a small problem. I started putting the carburetor back together but I don't know where the other side of this spring on the primary goes or if it may have broken off? These parts don't have a name I guess because you can't remove all these levers as they are pressed on. Why? Because they make money replacing or repairing for a cheap spring.

That means grinding off the screws that hold the plates. I can't open your picture. The spring looks wrong to me but I don't recall where it was. There's a lever towards what is technically the rear side that has a groove in it but that spring won't reach that far and it seems to simplistic to just rest a spring there. Just seems a an odd location with nothing to ensure the spring would remain there.. I've looked a many carbs online but the spring just seems to disappear in those pictures. Mine has a spring running from the distributor to the throttle which would seem redundant.

Definitely a Holley. These are vacuum secondary's. Does that make a difference? Which hole are you saying it goes into on that piece that has 8 holes on the side that is pressed in? I've added a side image so you can point or color the hole that spring goes in. I thought that hole was the one it was in. I guess I could pull the end around counterclockwise an entire time so it would be pressing against the trough.

That's a lot of shafts and springs but since you told me not to grind off the plate screws it's going to be real hard to do much with the spring other than to set it.

My favorite instruction to cover a wealth of tiny pieces and parts that a novice isn't going to remember and Holley's advice for rebuilding "Reassemble carburetor in reverse order of disassembly" are you effing kidding? That's the best they can do? Other than the "exploded parts diagram" that's smaller than the carburetor. Assuming you have all the parts and that none have fallen off. Just from looking at their general guide I see 2 missing parts already. My model doesn't have specific instructions.

It's an 80508-1 750 CFM vacuum secondary's has a square bore adapter in chromate. It's missing the screw that is used for retaining or adjusting, I'm not sure which, the pump cam. I guess that means I don't have one? Seems an odd thing not to have. Somewhere I read this is a single bowl feed but I have a duel feed now that may have been from pulling up info that comes up for other carbs like 80528 and others that I don't always realize that I've been reading other carb info.

This is the image I have of the exploded view but there are entire lines missing that should show the connection of parts. There's no differentiation of the 4150/4160 parts All they had to do was put the model on the parts list or even just a 5 or 6, a or b, etc. But that one little screw that we've been talking about just past where the spring connects into the accelerator cam or whatever you want to call I don't have on my carb but the other parts of the pump I do. The screw itself doesn't even show on the exploded view. I don't see what that screw does and how it ties into the pump lever. The pump lever has to ride on top of the spring otherwise it hangs on the spring. But there's no way that the accelerator cam "screw" comes anywhere close to the pump lever regardless of rotation. I have no understanding of how the two connect. I thought at first maybe it was the trigger for the secondaries but that doesn't seem to be.

I took images and videos before I even started this carb cleaning. Shortly after my phone stop working and I had to go back to factory setup which I've done many times without problem. However, this last time it destroyed my data on the SD Card. That has never happened. The next several weeks I dedicated to trying to restore the SD Card which because of how Google does things saw it as a device without data and so it grabbed it for it's own use which destroyed the structure and a lot of the data I did my best to get what I could but it's a tedious job and thousands of files and you have to sit there and open or at least attempt to open every file to see if it's even an image or document or some horsed up piece of junk. I'm still going through files when I have time but I can't depend on them or even finding the ones that are currently critical. I used my old camera to try to capture the disassembly using a tripod but that's not so easy to do either you moved the thing an inch and your out of the field of view. This has been just one mess after another.