I replaced the 3EE a couple of years ago in my 63, it has more cranking amps, more cold cranking amps than the 3EE, much lighter and maintenance free. The 3EE was always spitting from the vents in the plugs as well. I’ve owned my car since 1970 and can’t count the number of 3EEs I’ve replaced over the years, they never seemed to last long. I not fussy about keeping everything original and glad I switched to the 51. If your battery box is cracked or weakening SI sells an under the fender reinforcement piece for 63s.