360 using 318 motor mounts

I recently pulled the 360 la out of my 1971 duster and noticed it had unmodified 318 motor mounts. Meaning that the drivers side mount was only connected using the front two bolts, the rear bolt and tab do not line up at all. On the passenger side there are three bolts, two front and one back. My question is does this need to be changed? I drove the car for 5 years and the guy who had it before me did the same with these same mounts and we had no issues. But engine I pulled was a fairly stock 360, and I am replacing it with a 360 with 360 hp and 400 ft lbs. It's just that 360 mounts are now in the $400 range (when you convert to CND$ and include shipping to Canada). Another solution I have seen is to weld a tab on the bracket so the holes line up. Any advice would be welcomed. The car was originally a 318.