LA 360 or 5.2 magnum

Strength wise, that 360 will mop up the road with the 318. The 71 360 was a one year only engine that used pistons with a longer compression distance that got compression in the 9:1 range. No other 360 was like that........except the Magnums which have a shorter deck height to achieve the same basic thing. So IF the 360 is really a 71 and IF it has the factory pistons and they and the bores are good shape, use it. Since the 71 was a one year only engine, the industry uses the 72 and forward pistons as the replacement, so the 71 pistons are not available.