If you wanted to keep the twin 40's then i'd use the RST exhast manifold, turbo & intercooler.

If you wanted to sell the twin 40's and buy a normal TT compatible carb it'd pay for itself

Or bite the bullet and do a full rst conversion (fuel tank, pump, management etc... etc...)

If you want ease then i'd sell the twin 40's you have and but the TT kit and source a carb the TT kit was designed for...make up a boost pipe and your sorted.

Dan