magnum mounts

273/318 take different mounts then 340/360. If you have a set off a 340/360 LA motor then you're good, as all Magnums take that style. If you have 273/318, you'll need new mounts.

If you look at the Schumacher site for slant 6 to small block V8 conversion mounts, they list one for the 273/318 and a different one for 340/360.