At the time I have an Irvine 53 (2S) in her.Had to grind a slight bit of the mounting lugs off to get it to fit on the clamp mount.I have a Magnum 61 4S also.Before I take everything apart to try and fit the 4S in,do any of yall know it the engine will fit.The carb on the rear of the 4S is the question.Will it bang against the firewall or mount. Has anyone tried it??? Thanx a mil'