I have the Rifts ruleset and it should be automatically using the table from the Tomorrow Legion Book which doesn't change much from default SWADE until you get into the 12+ strength. My character with 12+3 STR had a load limit of 500. The same strength in default SWADE is 160 lbs. When mine loaded it noted that it was using the Load Limit extension even though I don't have it loaded. If you want to change it from what it's using, that would be a house rule.
It shouldn't be much of an issue in Rifts. I used to mark a lot of my gear as not carried as I left it in the vehicle most times. When I played a Combat Cyborg, I could literally carry 500lbs so it wasn't much of an issue until I started using vehicular weapons :)

