suppose we have a $p$-stabilized newform $f$ of classical level $\Gamma_0(p)$; then there is a unique ordinary deformation into a Hida family $\mathbf{f}$ defined over a finite flat extension $R/\Lambda$, and a corresponding representation $\rho: G_{\mathbb{Q}}\to \text{GL}_2(\text{Frac}(R))$ on a big vector space $\mathbb{V}$. Under some mild conditions, there exists a free rank-two $R$-lattice $\mathbb{T}\subset \mathbb{V}$.
I believe there should be some kind of autoduality for $\mathbb{V}$, and maybe $\mathbb{T}$ as well, in the form of a perfect pairing $$ \mathbb{T} \times \mathbb{T} \to R(1) $$ or similar, which is equivariant. Does anyone have a reference where this kind of thing is spelled out?