[Dave Z]

A 408 stroker... fitting that under the hood of a car not even designed for the 273...?

There's that guy (name eludes me, he's posted here often enough) who put 2.2 turbochargers onto slant sixes. Could try the same on a 273, a light pressure turbo with the carb... mechanical wastegate control... probably easier, and I don't think it'll boost power to the point where the crank would be clobbered. Yeah, it's a risk, but it would very likely gain you that same 40+ horsepower, and you could control it via the wastegate.

 

[Dave Z]

That 1976 Valiant is a very rare bird as well -- they made darned few 1976 Valiants and few of those were 318s.

If it's still there, I would appreciate the driving light lenses ... they were only amber in 1976 ...

(Is it white perchance?)