A big-block (including Gen 5/Gen 6 big-blocks) fits into the engine bay of a GM A-body without much hassle, but getting headers to fit was the real trick. Hedman offers two varieties of 13/4-inch headers (full length and 3/4-length) that work great. We opted for Hedman's 3/4-length headers (PN 68610) because they're easier to install, tuck up tighter, and provide added ground clearance. The headers can also be ordered with a trick hi-temp coating for an added price, but gaskets and bolts were included free. Before installing the engine, we test fit the headers to make sure they cleared the gear-reduction starter (included with the 502), motor mounts, and oil pan. If you prefer, stock-type manifolds are available from OPG.