carb choices
As for the 1.7 rocker arms, that will gain you a 6% increase in lift and no gain in duration. I dont know the exact lift of the stock roller cam but this could probably net you about .028-.030" in lift.
Going to the higher ratio rocker arms will net you about 4-5 HP at your peak RPM, and according to dyno tests, which usually show rpm power measurements in 500 rpm increments, you will net 1-3 hp at each measuring point. This may not sound like a lot but see it this way. If you have 5000 peak rpm, and adding all the gains together, based on the 500 rpm figures, you would stand to gain between 10-20 hp total out of putting roller rockers on your engine. Dont look at just the peak HP and Torque figures.
You have to take into consideration what the volumetric flow of the engine is capable of. Putting excessive carburetion on your engine will cause your performance to drop off, considering driveability, and throttle response at low end. Particularly running a double pumper with an automatic transmission.
I know this is going to stir up an age old arguement, over the carburation formula, again, but you can only put so much fuel air mixture in an engine.
With the standard carburetion formula, your 302 only requires 524 CFM of fuel air intake at 6000 RPM. I guess the way I look at it is why send a dump truck to move one shovel ful of gravel.
If you this were going to be a high rpm race vehicle turning say 7000 or more rpm, a 650 would be a good choice. But that would also require the mods to the engine to turn that high.
Youre engine, I take it is stock, so putting a 650 cfm carb on it isnt necessary or even desired.
Nor is a 2400 rpm stall converter.
Your stock C-4 has plenty of stall, and what a lot of people dont realize is that even with a stock converter, the more torque your engine puts out, the higher the stall will be, even with the stock unit.
On my 69 Mustang, the stock stall was 1700 RPM. After working over the engine, with no change in converters, my stall went up to 2100 RPM. Stall is the RPM, where when you have the brakes set and firewall the throttle, the engine stops gaining rpm.
If you would like to upgrade your cam, I would recommend going to the Ford E303 or F303, or an aftermarket grind compareable to them. These are good profiles and will give you a big boost in power without your suffering from driveability.
As for your vehicle weight, there isnt much difference in what your Fairlane weighs and what my 69 Mustang weighed.