yes it'll run fine as the ratios are only minutely out (0.02 IIRC-real world terms fuck all). But be careful which version of the 2wd beam it is...as the 3drs and the 2wd saph rear beam have different arms, the difference is the anti-rollbar pickups.....2wd saph is same as 4x4 pickup wise but the 3dr will require welding to arms or welding to the car to mount arb.

In short make sure its a 2wd SAPH back end NOT a 3dr one.

Other than that just put your 4x4 brakes over as theyre vented and the 2wd will be solid disk.

Dan