More HP out of my 318

318 exhaust log exhaust manifolds are restrictive, the TTI's would be an excellent choice, and will work great on the 340 later...and the best thing is, they don't hang through the steering like the cheap brands do. A good 2.5 dual exhaust set up with an H or better yet, X pipe will wake it up a bunch.
A faster advance curve in the distributor can't hurt, if you haven't done that already. I assume you ditched the points...
If memory serves, a 1.50 ex valve would be SMALLER than what it came with, should be a 1.58 stock....smaller isn't better....
Keep reading, you've come to the right place.
alan627b
Ah,I see you've got the exhaust already, you just need to get the headers....sorry I jumped the gun.