[mr0077]

The Ford factory (or reproduction) 2x4 linkage will work with the ERA throttle linkage, with some minor adjustment of the long rod that goes right now to your single carb linkage...it needs to be shortened about one inch if I recall.
I had dual 390 CFM carbs on mine, went to dual 600's. Because of the small size, I had the 390 carb throttles set up to be synchronized (open and go to WOT simultaneously), and it worked great until it ran out of air. I tried the 600's synchronized but I thought the driveability was not as good under light throttle use as the progressive setup, so I have the 600's set up to be progressive (one primary opens to about 40% throttle before the other primary opens, and both primaries hit WOT at same time).