I bought a 510 4 into 2 exhaust manifold since I have a 75 l20b and didn't want to use the combined ones. I have a Holley sniper to be installed. The plan atm is to make an adapter and use the 75 intake. I mocked it up earlier and I have to trim some of the bottom of the intake as it has that hole in the bottom of it. Id just bolt the plate that originally separated the manifolds. The engine is still in the machine shop.