F100 Project

Well , I just did a bit of research into the stock intake and exhaust valve diameters for the heads on my 351C and it appears to be a 2V open chamber head  that was fed by the Carter 4 barrel. But having said that , who cares....

But what I did find interesting yesterday was a guy by the name of Mal Wood in queensland , Australia has manufactured a an extension housing which converts your T5 gearbox to a midshift gearstick position, which is great if you want to keep your bench seat in the F Truck and run a T5.

http://malwoodauto.com.au/tremec-t5-centre-shift/

Yes, that's exactly what I expected - 4bbl manifold and carb, and 2V heads.  Sounds strange, but if you were to compare 335 Series 2V heads with Windsor heads you'd see that the Windsor's ports were much smaller.  So the 351C and 351M had plenty of high RPM potential as well as low-end grunt.  But in the case of the M the cam was retarded and the compression was low.  Apparently that wasn't the case for your 351C.

As for the tranny, the T5 would be a nice addition.  I don't know what options you had for transmissions, but since the Cleveland engines had the small-block bolt pattern they had a wide range of options here.  However, the bench seat does present some problems, and that is a neat solution.