273 mild build-----

If you're keeping the drivetrain mostly stock, IMO the cams recommended are a bit steep.

The 273 HP cam had .425 lift I/E, 248º duration, 46º overlap. The engine had a 10.5:1 compression ratio. This cam with a lower compression ratio will be "soft", especially on the low end. As far as I know, no one is producing the HP pistons as a stock item.

The Edelbrock Performer 2176 is an aluminum dual plane 4 bbl manifold that will match up with the stock heads. The factory HP manifold is iron and a single plane unit. The Eddie sits a little higher than the stock unit. A cable type throttle linkage will work fine, but a factory kickdown linkage will need a little "local engineering" to work. Lokar and Bouchillon Performance have cable kickdown linkages that will work.