It's possible the motor is a magnum even in 91 I believe there is some crossover. 360 la motor wont have the 302 casting heads,but it might have the 308 casting head,open chamber like all 360 heads but has a much improved exhaust port which breaths much better.
I know the 318 came with roller cam as early as 85,but not sure when the la 360 made the switch.
