If I did wanna keep the stock parts would my rear clear my 37 with offset rims stock ?
In daily driving on road scenario, the rear should not rub with stock leaf springs assuming your leafs are in okay shape and not sagging. Hopefully the airbags prevented sag. I ran 37s for awhile with stock leaf springs and it was fine on road. If you go off road, there is a decent chance the tire will rub on the flare especially the bolt heads with some articulation. Bottoming out the rear suspension by jumping or whoops or whatever will definitely rub and probably damage the flare/fender.
However if it was me, and I was keeping 37s and the eibachs up front, I'd put Deavers or Icon leaf springs in the back. Safer and marginally more expensive I would imagine compare to getting brand new OEM replacement parts to go back to stock.