i thought the commentators said 80kg, either way he is probably one of the heavier riders in the peloton. the stage had something like 4700m of elevation gain
Internet says Indurain was 6'1 - 6'2 and 76-80kg.
Closest comparison for Indurain at the moment in terms of TT ability/climbing ability is Van Aert maybe? Who is also in a similar in height and weight.
He was reported to be 75-78 kgs. Don’t know how accurate that was, but he wasn’t as heavy as 90 kgs.