318 or 360!?

How do you tell the difference between the two? We just took the engine outta a 74 dodge sportsman motorhome. The model number off the door jam said F30. What are the appearance caracteristics of each? I dont have any numbers. we took the motorhome to the junkyard already. I will check for numbers on the block tommorow to help. but until then is there anything you could tell me? Could it be a 440? Im guessing its a 360 but idk. btw its a 2 barrel carb on there. if that helps.

Look at the torque converter,the 318 and 360 torque converters are differant in one way.The 318 converter has a counter weight on it and the 360 does not

I just had the torque converter in my hand an hour ago. im pretty sure there was a counter weight on it. Thanks for your reply. Even thou i was hoping for a 360 i guess a 318 will do.

If the engine came from a 74 motorhome, it was probably a 318-3, unless it was not the original engine. The engine i.d. was on the front of the 318/360 block, right next to the joint with the engine head. It was just stamped in, so isnt easy to read if its greasy or rusty. I forget whether the i.d. was on the right of left bank. If the motor is still in a vehicle, its close to impossible to see. Dont be fooled by the # on the sides of the block. That is just the rough casting number, not the engine series.
The 318-3 is a very strong light truck engine. If you are going to use it in a car, remember its compression ration is about 8 to 1, and its 'truck' cam has a torque peak about 2800 rpm. The 318-3 distributor is also limited in centrifugal advance - only about 15°. This is because it never needed to run above 3600 rpm when pulling a motorhome. It would have had a different vacuum advance too. If it were the motorhome version of the 360 (360-3) it would have been similarly aimed at truck use; a durable slow speed 'pulling' engine. The 318-3 would also have different head gaskets than the 318-1 in the passenger cars, better valves and valve seats. It may or may not have had a heat riser passage through the intake manifold. I definitely took colder plugs that the engine in the cars/vans/pickups had. Its water pump was different - more vanes, a different water pump housing I think.


For info: 318's and 360s are small block mopars, and the distributors are at the rear of the motor. On the big block mopar, like the 413 and 440's, the distributor was at the front, on the passenger side.