There might be a problem with suspension movement trying to move the engine and trans front to back over bumps, It would depend on the type of Motor mounts you use. and how you attach to the Lower Jag arm. Stock jags use a lot of rubber in various mounts, In the old days the racers eliminated the rubber because the rear suspension movement was trying to steer the car. I used the CCR plans putting a Jag rear in my son's 22 Dodge Lakester. With the CCR plans you use the Stock Jag rear rubber in the Hair pin bracket.