It waries greatly depending on vehicle weight and tire and rim size. As a general rule the tire should sit flat on the road and the eazyest way to "see" if its over inflated is after the tires clean drive on a dusty level road and see if all the tire is contacting the road and getting dirty or...
Just looked at the bumber on and off pic's and it looks possibly like the bumper could be coming in contact with the core support on the passangerside above the bolting location and depending on how its atached that could be a likely place to inspect
Id say start it up put it in gear keep your foot on the brake and flex the engine mounts foward for drivers side reverse for passanger side. You might need to give it some gas and alot of clutch but thats the easyest way to test them. It helps to have some one standing to the side of the rig to...
My opinion of said voltage problem was to charge it cuz it be week my friend. Also being that it sounds a little like you dont understant the electric side of things extreamly well please check up on understanding series and paralell batterys will EXPLODE.
A battery should have 6 cells...
Threw the adventures of trying to squease every living drop of life out of a battery either bought new or used in a vehicle Ive purchesed. The best thing Ive found is what a few people said Jump it in paralell to a solid plate lead acid battery and then I hook up a slow solid state charger and...