Maybe this will answer some questions?

Well, looks like a pair of 40mm carbs, electric fuel pump, 009 distributor, MSD coil, the obligatory chrome tin..at least what's left of it, no tin to body gasket..not that it much matters because the tin that's there wouldn't seal against it, plastic spring loaded pushrod tubes, 12 volt conversion to a degree, header of some sort, no heat,firing order looks correct, looks to have a second wire off the - side of the coil(same pole as the green wire from the distributor) leads me to believe there is a tach, heads and push rod tubes look very clean, may have low miles...
That being said, those carbs would be a waste on a 1600 in more ways than 1. They are not cheap, I would guess its not a 1600, but that's just a guess.
(1) Did the car ever run well since you got it?
(2) if it has a tach does it jump around when it's running, jump from say 1500 to 2500 or 3000 and back to 1500?
(3) how long has the car been sitting/not driving on the road?
(4) if the answer to #1 is yes, when did it start running bad.
Also those intakes get in the way of the plugs as you have found out, you better remove the one on the side with the jacked up plug threads before trying to repair,you dont have to remove it all the way just move it over or you may end up damaging the head to the point of no return if it's not already there. Best to cut out access panels on both sides inside the fender so you can go straight to the plugs. Even then it will be very tight especially if it's running the large plug type(13/16 vs 5/8)