Constant MAX_STANDARD_SCRIPTSIG_SIZE 

pub(super) const MAX_STANDARD_SCRIPTSIG_SIZE: usize = 1650;

Maximum size in bytes of a standard transaction’s scriptSig (zcashd MAX_STANDARD_SCRIPTSIG_SIZE). https://github.com/zcash/zcash/blob/v6.11.0/src/policy/policy.cpp#L92-L99