Alvis Sp25 / 4.3 Twin Exhaust Manifolds Available Now By In NewsPosted November 26, 2020 Available in stock now: newly cast Alvis Sp25 / 4.3 twin exhaust manifolds. All gaskets and studs are also available. We have limited stock, so please call for pricing and to place and order on +44 (0)1981 250 244.