You can jack your plane one main gear leg at at a time using a jack pad which was an original grumman part with a call out number. Here is a picture of that part. This one had been painted so we know it belongs to the shop. The two holes go over the nuts on two of the main gear bolts down by the tire.
Has anyone fabbed a set of these themselves or is it preferred to buy them? I saw them in Fletchair’s catalogue for $30 a pop but it doesn’t look like it’d be difficult to weld one up.