I have a 1977 Dodge Class C RV with the 360, since new & I switched to 4 barrel & headers with Dual Exhaust & (to my est.) I gained about 10 - 15% more power, but hills, fully loaded & with a boat, still bogs it down like it has a 2 barrel.........but seems to pull a lot better.I also noticed that my Fuel mileage incresed while towing 1 -2 miles per gallon.I am in the process of locating a Overdrive unit for it.
I believe the swap was worth it at the time, but with prices now, not sure if it is beneficial
Dodge rated horsepower for 1976 360 engine:
2 barrel = 180 @ 4,000 rpm4 barrel = 200 @ 4,400 rpm
With the different Cam & recent rebuild, the horsepower could go either way.The only way to get accurate horsepower readings would be on a Dyno