73 Valiant 318 performance build Ideas.

In the case of a mild performance build, I'd probably go with a factory four barrel intake, Ededlbrock base performer, or a weiand stealth (preferred, 318 sized runners from plenum to port). I'd probably run the dougs D-453 headers. If your going to rebuild the transmission anyway, a good converter (probably a quality reproduction of a factory high stall) would be worth some improvement, especially with the 3.55s. But, have you done a compression check yet? 8.5:1 is probably a stretch for this engine. Can you get any specs on that cam you can share with us? By virtue of 3.55 gears, you may be able to run just a shade more cam in it. It would take some guide to retainer and possibly spring seat work, but this cam is looking really good for this on the Howards lobe list with 128 degrees at .200 lift. I don't know the ICL on it yet but given the design parameters it looks to have had four or more degrees of advance ground into it.
Howards Cams Hydraulic Flat Tappet Camshafts 711381-10