As I explained earlier, the IS-10 is the T-10, officially. IS-8 was the early development prototype.
The confusion comes from the development of the IS-10, which started as IS-8, then IS-9, with minor versions as IS-10A, IS-10B, IS-10M and M2. But the IS-10 was renamed to T-10, due to political changes in the USSR.
IS-10 (called Object 730) was the last tank in the IS series.
During the development versions had the names IS-8 and IS-9.
After Stalin's death in 1953 the name changed to T-10. Type 1 produced 1954-57. Total production unknown. A, B and the M-versios in 1962. 1963 equipped for under water driving to a depth of 5 m. Speed of fire was slow (3-4 shells/min) because the shells were devided and had to be put together before loading. The gun was rather immobile (upwards) when going downhill. Until 1980 the best protected Soviet tank and a T-10 shell could penetrate 450 mm thick amour at a range of 2000 m. The M-model had ABC-protection and infrared seeker for combat at night. In 1995 it was renamed into IS-10. With 122mm gun, except the IS-10-M2 variant that uses an 130mm gun.
Variants are IS-10, IS-10-A, IS-10-B, IS-10-M, and IS-10-M2
Weight: 52 tons
Length: 10,6/7,04 m
Height: 2,43 m
Width: 3,57 m
Armor: 20-250 mm
Gun: 122 mm
Engine: 12/520 kW
Speed: 42 km/h
Range: 250 km
COST PER UNIT: R1.160.000
Source: http://z4.invisionfr...Dept/ar/t11.htmBottom line: IS-8 is NOT T-10, but the very first prototype, which differed greatly from the final version of the IS-10.