IMO, the RV style cams are worthless. The ones I have been familiar with resulted in less power and reduced mileage.
When I built my 235, I used the 848 head with a mild port job that has now been milled twice to get flat. Got one of Patrick's 252/264 grinds Checked the valve to piston clearance with clay. It was close, but I have forgotten the number. Left the points distributor in along with stock manifolds and Rochester 1 bbl. Eventually I put 4.10 gears in the old gal, later a Pertronix ignition. She has a rumble known only to those with a good ear. Idles at 500 rpm. Will haul 2 yards of soil down the interstate, in the summer, at 55-60 mph without overheating or straining. And she will turn about 5,000 rpm, with a top speed of over 100 mph.
At the opposite end of the spectrum, my friend has built a 1/2 ton with a 261 that is about 300 hp. Professionally ported head, an old full race cam, Fenton headers, Offy dual carb intake, dual Holley-Webers, Uni-Lite distributor. Idle speed is about 1,000 rpm. Tranny is a Saginaw 4 speed. He once lit her up, and was soon over 6,000 rpm in 4th gear when he shut her down. His only complaint is not enough carb, looking at going with dual Rochester 2G setup, which we will need to do some engineering to make it work.
You don't have to have all of the add-ons to have a good running truck. They do have their place, but need to be balanced.
I grew up with guys who pulled the 261 out of the farm truck, put in a 3/4 or full race cam, hand sanded the ports in the heads, and opened up the B model carb to put in a car that would beat the newer cars. We learned how to make power on a shoestring budget.
