Originally Posted by
rabel
Thanks again for your help. I just bought the new engine after speaking with Briggs tech support. Officially, the replacement engine is the exact same model, but unofficially any of the models should work assuming the same drive shaft length and width. The exhaust system is the same for all of these Briggs models. I got a great deal on that 25hp engine and will be installing it over the next couple of weeks, hopefully before it's time to mow again.
I'll update this thread when I'm done, for other's future reference.