Been having some annoying issues with my single barrel carter on my 85, thinking about a new/upgraded carb, anyone out there know which 2bbls will fit without much/any modifcation?

 

There are adapters which allow a two barrel carburetor to be mounted to the original "log" intake manifold. Others use either a Clifford or Offenhauser 4 barrel intake with an adapter for two barrel. Many have posted about Motorcraft 2100 or 2150 carburetors.

Your 1985 with 4.9L engine originally came with a computer controlled carburetor and distributor. If not required to meet emmission standards where you live, you might consider simply doing a Duraspark 2 conversion. Use the "search" feature at the top of the page and type in "Duraspark conversion". You will find much to read about.

I have done this on my 1986 with great success.