For years, the EPA was not messing with RV's, commercial vehicles, but really pushing on little private vehicles. Well not that many years, EPA started all this in 1972, this is a 1982. Has, no EGR valve, getting by with closing the exhaust valves early, fixed, not like later vehicles with variable, but apparently enough so you will not burn out the exhaust valves. No catalytic converters on this thing, comes with factory dual exhaust. Exhaust pipe, muffler, and a tail pipe on each side.
Its a low speed high torque engine, headers wouldn't help that much, 3,000 rpm is just about tops.
Bit wrong on that engine driven fuel pump, would be dead if the diaphragm did break. To be on the safe side, replaced it with a brand new Made in the USA Carter fuel pump that you can buy today for 18 bucks, compare this with that POS tiny little fuel pump in like my 88 Supra uses where my crooked Toyota dealer wants 450 bucks for!
Use to be just one inlet and outlet on these mechanical pumps, but this caused vapor lock, this one has two outlets, one to the carb, other returns to the fuel tank for a constant recirculation of the fuel to solve this vapor lock problem.
Have to admit, the electricl fuel pump is a bit of a mystery, an inline pump with an inlet and an outlet, looks just like looking through a small tube, so does not interfere with the mechanical pump when off. But when switched on pumps like crazy. Don't recall the name, but purchased an identical one for my boat. Thing is, when these things sit for awhile, the carb bowl runs dry, and may have to crank the engine for 30 seconds or so to fill it up. But switching on the pump for about ten seconds, hit the key and the engine starts instantly.
Pace Arrow has another reason for mounting this extra pump and even has a switch on the dash to fire it up. That rear tank is so far back there, the mechanical pump cannot handle it, and will stall when going up a hill.
Dash has a DPDS on it, top selects the fuel senders from either tank, bottom only has two wires on it, for the front tank energizes the tank valve to shut off the rear tank to the front tank. Feed gas is 5/16", fuel return is 1/4" hose. Looking at a hundred buck valve here, glad that is still good.
This make sense?
One thing that really tees me off, good always buy good gas, not even sure what we are buying today with an EPA with over 155 blends. Have to use ethanol free gas in this thing or will end up with a ton of corrosion. Pray that guy filling the tanks at these gas stations is half awake. But apparently got water in my rear tank, was running fine until I stopped at a gas station, and usually pick one that looks busy.
Your writing, 
