Whoops, I'm sorry. I should have been more clear. I mean I was thinking of using the Magnum pistons AND rods in the LA engine. Would that work, or is the rod different on the crank end as well? The only reason I ask is because the magnum engines are rated as being 9 to 1, and the LA is 8.5 to 1. I don't know if the magnum heads on an LA block would boost compression, or if the magnum chambers are around the same size as the old 70s 318 LA heads.