Picking the right Quadrajet

[gnvair]

I have a 78 Malibu with a factory 4 speed. It still has the original LG3 305 with the Rochester 2 barrel (GM didn't offer the Quadrajet on a 305 until 1979.
I want to swap it over to a 4 barrel. I have in my parts stash an aluminum L82 intake with the provision for the hot air choke like the 79's would have.
In my possession I have 3 Quadrajets:
17059207 (this appears to be the correct carb for a 79 with a 305 and a manual transmission)
17059216 (mfg by Carter). Another 79 carb for an automatic trans application based on the throttle lever)
17058203 (I believe this is a carb for a 78 350 with manual transmission for a Corvette or Camaro).
The first carb still has the caps over the mixture screws.
The second carb someone removed the caps.
The third carb has the older exposed mixture screws with the slotted heads.
Which one should I use and why?
Lastly I eventually want to install a later model Vortec 350. Could I use the same carburetor and if so, what would I have to change to compensate for the displacement change.
Thank you in advance!

[gnvair]

I was also curious if the base plates could be swapped around on the 76-80 carburetors meaning swapping a base plate with the exposed mixture screws for one that was originally sealed.

[Cliff Ruggles]

Bad idea swapping baseplates around.  They are similar but not exactly the same from part number to part number so they may physically bolt in place but not work correctly.......Cliff

[gnvair]

Thank you for your response Cliff. Would you be able to comment on my questions in the first post?

[77cruiser]

I'd used the one that looked to be in the best shape.

[Cliff Ruggles]

Those carbs are pretty much equal so use the one in the best shape.  Convert to E-choke and set it up for the stock 305 engine.  They really shouldn't need much help beyond good parts to hold up in this new fuel but I always replace the jets and usually the primary metering rods as well.

The used parts almost always show some wear and I like to give them a little more fuel plus wider range of adjustment with the APT system.

Plus you never now if someone got there before you did and drilled out the jets, replaced them with larger or smaller ones, etc. 

New power piston spring as well, 99 percent of the time they are "soft" from light surface rust and it's just a good idea to replace them anyhow.......Cliff

[gnvair]

Do you sell all of these items? I am planning to rebuild one shortly to put on the car.

[Cliff Ruggles]

We sell everything you would want for the Q-jet, and the highest quality and most complete kits in this industry.......Cliff