The exact number is hard to give as each dash variant is slightly different in weight.
Since you asked for the installed difference, assuming they each have the same options installed (prop, mags, carb, alternator, probes, etc.) then the difference in installed weight should be close to the same as the difference in raw weights. FWIW, my Catto prop is 9 lbs, a FP metal prop is 40+ pounds, and constant speed prop can go much higher than that once you add in the prop governor, control cable, plumbing, etc.
The following is from:
http://www.aviator.cc/aircraft_engine_weights.html
Engine_____Horsepower_Weight
O-235-C1B_____115_____240
O-290-D2C_____140_____263
O-320-A2B_____150_____272
O-320-A2C_____150_____271
O-320-B2C_____160_____277
O-320-D2A_____160_____277
O-320-E2A_____160_____277
IO-320-B1A____160_____285
IO-320-C1A____160_____294
IO-320-E2A____150_____280
O-360-A1D_____180_____284
O-360-A3A_____180_____285
IO-360-A1A_____200____320
IO-360-B1B_____180____295
IMO-360-B1B____225____274
