Based on appearance that is a 235. Further, based on the heater hoses, though I can't see the water pump, it appears to be a 55 second or later engine. The radiator appears to be dropped in the mount, which is necessary for the fan to clear the lower radiator hose. Patrick's (former AZ chev parts person, now gone to his last reward) produced a pulley to move the fan back toward the block for the 235 2nd engine. You had to press the pump flange further onto the shaft. Patrick also produced an alternator mount to replace the generator mount. You could slot the holes where it mounts to the block and slide the alternator as necessary to align. It may also have come that way. But you can only go so far or the alt. pulley will hit the fan, at least with a high pitch fan. If you want to run AC there are various brackets made by several vendors. Patrick used to make one.
Another solution is to find a 2 ton radiator, which has larger tanks and a 3" core; and team that with a high-pitch 5-blade 16" fan. You will not have cooling problems even in AZ as long as everything's clean. This setup does require that you mount the radiator on the front side of the radiator mount and cut the welds to move the cross piece to clear the top radiator tank. Drill a couple of holes to bolt it back in. Do not go without. You'll have to modify the cross piece to clear the top tank. On a hundred degree day I pulled my 4,000# camper north from Page and on up to Torry UT. Never went over about 200 deg on the temp gauge. I also have AC, with the condenser mounted below the radiator, which is necessary for that kind of driving.
Before settling on tires make sure that the rears are at least 32" tall. These trucks were already slow with 7.50x17, like 48 MPH at 2500RPM and 3300RPM at 60MPH. You can't run 3300 RPM for any length of time; 2900 maybe if you want the engine to survive but you won't like the fuel bill. You could hunt up a 4.56 pumpkin from a 3/4-ton; or even a 4.10 from a later pickup if you don't plan on heavy loads.
Ive researched the tire/wheel situation repeatedly over the years and if I had it all to do over again I would go with a 2.25x19.5. These tires are used on thousands of motor homes and are readily available, plus they're 32.5 inches tall and carry 4500 lbs. each. The wheels will not look original unless you search wrecking yards every weekend from now to kingdom come. I'm told original-looking wheels can be found. But you can always buy new, steel or alloy.
