grade 8 three point foldie bolts. and weld the back side of the foldie just a bit.
if it is only welded in the back and were the picture says it is easy to cut off. if ur dad works in a body shop bolt it first, then welded it in. cause the bolts will lock it in place to start. then the welds will secure it. so the foldie will not have any movement. at all. and will not squeak. but this will put un nessare stress on the middle and drop out of the deck causeing a bent center and a cracked deck. but the foldie is solid. so if you do this i strongly recomend you get full deck bar reinforcement
if it is only welded in the back and were the picture says it is easy to cut off. if ur dad works in a body shop bolt it first, then welded it in. cause the bolts will lock it in place to start. then the welds will secure it. so the foldie will not have any movement. at all. and will not squeak. but this will put un nessare stress on the middle and drop out of the deck causeing a bent center and a cracked deck. but the foldie is solid. so if you do this i strongly recomend you get full deck bar reinforcement