1974 318 duster. Can I port/polish these heads and get enough power out of them?
Hey all. I bought this duster and it already had some goodies. Holley 4 barrel street avenger carb and edelbrock low-rise intake with a 3" flow master dual exhaust. The exhaust manifolds are the originals, but I can probably change them out and weld them to the 3" flow masters.
Can I take these heads off, port and polish and keep them? I don't have the money to do much, and keeping things cast is really fine with me. I'm also thinking about putting in new piston rings and an oil pan and rebuilding or just servicing the 904 that came in it so it doesn't leak. And then maybe spending some money and making the rear end a sure grip if they make it with the 8.25. Was also going to put a decent cam in it and change everything to where it works right.
Thoughts? I don't have a big budget at all.
I can make a 318 head touch 190's with just a really good .070 wide face 4 angle valve job.
The stock cam is X amount- .395/.400ish of lift..with rocker arms that are advertised @1.5 , but are really less..
Low lift flow would be the focus if staying with the stock cam n only working the heads. Porting will increase flow at all lifts if you know what you're doing... but a good 4 angle valve job is idiot proof.imo
Otherwise...just open the bowl, profile guides, mildly work the straight atop the ssr approach to the turn itself...with the common wall. Leave lip/tiny edge just before it turns on that side of the approach.
Open chamber near seat like a cone, angled to the edge of the chamber. Don't hog it flat to the chamber wall.
If you lay a head gasket on the deck line it up with some spark plugs or what-have-you corks, use a wide tip marker for 318 and that distance of the line you leave should be the bores actual edge and let you know how far to go. With 360s and 340s you just use a regular Sharpie fine point and that's near perfect to show bores actuall boundry line/edge.
Lightly flatten 'not completely' the roof kink in exh ports, lightly roll the ssr over to the floor 'u shape and not flat angled back. Make a venturi if you can in far side bowl/throat.
Snap gauge width at ssr of exh and exit and open them accordingly. Pay attention to the ports design shape and how we're trying to work with that on the exhaust.. 'ends vs the center exh ports' for instance.
