Lets increase T34/85 range to 60 and pen to 200-180 for the same reasons in relation to SU-85!
After all they had the same gun!
And lets have the SU-76 get the same penetration as the SU-85. Because they don't even use the same gun.
Regarding OP, maybe a penn buff could be okay, but maybe increase in fuel cost or decrease in ROF? to compensate? I mean it is already a solid vehicle as it is.