If that 71 360 still sports the original ONE YEAR ONLY pistons, then it has higher compression than ANY other year LA 360 and probably DANG CLOSE to the 5.9 Magnum, because they had one year only pistons with a taller compression height and that gave those engines around a true 9:1 "or so" compression. So yeah, it'll suck that 750 down and blow it out the tail pipes.