Briggs engine swap?

[Aaron SEIA]

Have an old Country Clipper with an 11 horse Briggs Model 253707. Found a nice looking Briggs 12 horse model 281707. After I make sure the 12 horse runs but before I take the 11 horse off, will these 2 engines swap (mounting pattern and crank style)? A tired 11 horse on a 42" zero turn just isn't enough. Figured a 12 is a 10% increase in power and the $15 I spent on the engine beats the $400 it'd take to replace the mower.
AaronSEIA

 

[DandK]

Yup

 

[rustyj14]

Yep-an easy swap. Been there, done that. Everything should be the same as to fitting in and on.