[55blacktie]

American Y-block 2-barrel intake manifolds have a 3-bolt carburetor pattern. Unless your 2-barrel manifold has four bolts, the Mr. Gasket adapter won't fit.

As far as modifying your 2-barrel manifold to 4-barrel is concerned, anything is possible, given that you can find a machinist with the skills to do it, and you are willing to pay the price. In my opinion, it would not be worth the investment.