LA 360 or 5.2 magnum

Not sure that your 360 has more compression than the 318. The 318 has 302 heads which are closed chamber heads. Anyways, the A518 is a heavier tranny than the 904 and if the A518 has the stock converter, it would be a little tighter stall than the 904. But back to your question, this particular 318 vs the 71 360, it might be closer than what one would think. The roller cam and swirl port closed chamber heads really adds low end torque, which in stock form is probably the biggest advantage the 360 has on the 318. We know there is more potential in the bigger motor, but in this situation "as they sit", it would be closer than most would want to admit. But IF the 360 has excellent compression (those valves would tend to leak if too much unleaded fuel had been run through them), and is up to snuff, I say the 360 pulls this one out. But one thing not right on the 360, that 318 "up to snuff" might pull out the win, and I'm talking same tranny's and gears (904 and 3.55's)