318 low budget heads change

The 302's port out very well and should be done to a 360 sized window and etc.... The biggest reason for the 302 heads mention is the ability to port out with a small chamber as cast. As cast, it is fine for the everyday driver with minimal cam increase.

Working a 340/360 head may be easier, but it is the milling the deck and then Intake face to get it where you want it that "can" be an issue. (Thin valve cover rails) On my old 318 Duster, I went with the stock heads from the '79 vintage engine. It was fun in the street with good mileage.

Also, when I see budget, I figure that it is ether spend the normal amount for a head rebuild or spend 1-1/2 - 2 times more for a performance build. Aluminum heads, aftermarket rockers etc....
It's a bit more than rebuilding stock parts of replacing them with stock parts. And there is where budget goes out the window.