The carburetor adapter was discussed in this post way back on page 149. Unfortunately, I quoted the wrong Edelbrock adapter number, possibly because you had something close on-hand. Search as I might, I can't find the picture of all the carb plates and adapters you had posted at one point.
Regardless, if you've got smooth throttle opening all the way to wide open throttle, you should be OK.
Check throttle function closely; if it hangs up during passing or a foot-down merging manuever, things can get very exciting in a hurry. I'd be very surprised that the throttle opens all the way with that carb on that intake. If it doesn't open all the way but doesn't hang, you still won't be able to adjust your kickdown linkage, which
requires the carb be at WOT. Look down the bores and make abso-damned-lutely sure.
My wheels are spinning but I'm not getting anywhere!
brought out the carb, tried the new plate & it still seemed to catch, added in one of the old plates & throttle opened smoothly.
I'm gonna need some kind of adaptor here, much larger thread on the carb.
You need a
5/8"-20 gasketed straight thread to 5/16" inverted flare adapter. Edelbrock doesn't make one, but
this one should do the trick. Stop attempting to modify the line until you have the right part in-hand. All of the aftermarket brand-name ones I found were for 3/8" fuel line. Your line should be 5/16".
All this carb nonsense is why I suggested a ThermoQuad. It just plain fits, and it's a much better carburetor in literally every measure.
While we're on the induction subject, let me know a price for the Strip Dominator intake if you rid yourself of it.
sticking with the carb theme, I went to put the new adaptor on & the holes didn't line up, so I pulled the yucky one off the other carb & that fit, I think I have the throttle piece in corectly?
Both of those parts do the same thing and mount similarly. One has a bend (made by Edelbrock), one has a cutout for clearance (made by Holley). I
believe the Holley part uses a washer between the adapter and the throttle shaft bracket at the lower mounting hole rather than the fancy bend. I've never set one up on an Edelbrock because I don't use those carbs.
looking at my kickdown junk the black ones came with the ebay kickdown I bought to replace the one I stole for the 73 the silver is off the 73.
they all look the same except for the large hole, one on the left matches the 73 one, the black U shaped bracket is bent I can steal that off the old 73 one.
Which black bracket should I use, does it matter?
Considering every throttle-cable bracket you've got there is a two-barrel part, I'll go with "none of 'em" for $400, Alex. The RH black bracket
is for a '74 360, but it won't work with a four-barrel. The other two are 318 parts. The throttle-cable clamp stud is higher and further back on the 360 part.
Two-barrel and four-barrel parts do not interchange. The kickdown parts are different, the throttle-cable bracket is different, and the throttle cable is different. No amount of mixing, matching, bending, cutting, and swearing works. You'll either screw up your throttle travel, smoke your transmission, or both. I fought this battle a lot when I had automatics. The last was on my Fifth Avenue, way back in 2004, but by then I'd learned to get all the parts from the same car with the right carburetor and transmission.
I have no idea what that "dohickie" is other than trash. It's not a Mopar part and I can't imagine what its function might have been. Toss it. The weird little black bracket to the right of the RH bracket that looks like a throttle-cable clamp with an extra stud at a right angle is exactly that. It's a cruise-control throttle cable clamp. The silver one behind it is the standard clamp you'll want to use unless you're installing cruise. If you've no use for the cruise clamp, let me know.
The OE part number for the kickdown rod is 3751570. The throttle bracket is 3577561 and should look like this (except blue):
I think I have one of those throttle brackets lying around, in the correct color even. Let me do some digging and get back to you on that. If I can't find mine, Van's does offer a reproduction.
This is a photo of all the factory 1974 360HP stuff, from an ended eBay auction I found using OE part numbers. He had two sets; each sold for $275+shipping.
Here's the factory parts book's diagram of the kickdown assembly. They only show one diagram for small-block, so ignore the fact it shows a 2-barrel. The assembly goes together the same, even though parts don't interchange.
That orange-colored bit is
not that inexplicable piece of metal hanging from your silver linkage parts, it's the throttle arm bracket (to which the adapter is bolted on your carb). It isn't really 100% clear in the diagram, which is why I highlighted it.
Other than possibly having the throttle bracket, I can promise I don't have any other parts for your kickdown. All my automatic stuff went away years ago.
sticking with the carb theme, I went to put the new adaptor on & the holes didn't line up, so I pulled the yucky one off the other carb & that fit, I think I have the throttle piece in corectly? 
they all look the same except for the large hole, one on the left matches the 73 one, the black U shaped bracket is bent I can steal that off the old 73 one.
there's another dohickie on the old 73 one, do I need that?
I was short 1 washer & got a match in my junk drawer. 
I had gone to my book, your diagrams are soooooo much better! 
& finally (well for now anyway) these are the adaptor plates I have now, if buying the other is a better fix I will do it.
then I tried the heat gun on the carpet, didn't help much & it burns that jute pretty quick!!!
