Any tips on fitting the US Car Tool Sub Frame connectors?

When I bought mine for my 65 Dart, I was told by friends to get the chassis on the stands on a level level level floor, also, I checked the height of my jack stands (a.c. delco) to be sure they were all the same height while supporting the chassis. Definitely not on the rotisserie until tacked securely in place. Be sure front and back of the chassis are resting and are supported in the same place...right and left side....then use the door margins to see if the chassis has any twist. Yes, jack the connectors into place from the bottom, but do not over jack where the chassis is off the supporting jack stands, and with the carpet removed (fire), weight the inside of the floor pans to push down a bit. A bit tight with the jacks, and a bit weighted from above, then scribe and cut/grind to fit. A proper door margin all the way around, i am told, will determine any chassis twist. Having the front suspension on or off does not make a difference based on instruction I rec'd from USCT....I think off is better. Not an expert, but hope this helps you out. Old Dart 66