i just bought a set of mac shorty headers 1 5/8" and am wondering if they will fit into the stock exhaust manifld spot without a problem on a 351w. i've heard that there may be clearence issues with the starter but the header doesn't even come close to the header

Also what type of gasket is recommened for the header

 

The only way to truely tell is to remove the old manifolds and install the headers and see if they'll fit. I run a boosted applications on my 5.8 and I would recommend Mr Gasket Ultra Seal gaskets....14psi and no leaks with these gaskets, and you can pick them up at almost any auto parts store.