[Abraham]

I only have intimate knowledge available about the M-26 (Pershing) and the M-26A1E2 (Super Pershing)

M-26:
Weight 47.5 tons.
Suspension: Modified Christies system.
Ground pressure: 3.5 pound per sq. inch (Sherman 7 pound p/s/i)
Engine: 550 Hp. Ford inline engine
Mobility: excellent
Speed: 56 km per hour
Armour: (front glacis) 4 inch hardened at 45 degrees (superior to the Panther.
Turret with power traverse and gyrostabilizer.
Gun: medium velocity 90 mm M1 (2,750 feet per second)

M-26A1E2: the experimental 90 mm T15E1 70 cal. gun was added with some modifications to the cuppalo (counterbalance etc).
It produced a muzzle velocity of 3,850 f.p.s., 600 f.p.s. more than the 88 mm KwK43 gun of the PzKw VIb King Tiger. It was the most powerful tank gun of the war and it's shell could penetrate any adversary.