273 motor mounts --- source?

If yours are thicker, they are probably van? truck? mounts which I tried to use in mine before going to "spool" mounts, and after doing so, I see why everybody "preaches" them.

When I swapped the 360 into the car for the 273, I used new "parts store" mounts, and in less than a year the left side had separated. This was a VERY lukewarm 360 / TF/ 3.89 rear on the street. I'd guess 270--300 hp

The thicker biscuits seemed to cause header clearance issues in mine