Briggs engine swap?

I also have a 5211 with a shot engine (let the oil run out) which now burns oil. Am looking at a used 5212.5 unit. Engine is clearly larger and the control panel is different.

I was thinking about rebuilding the 5211 but at $500 to $650 it would be cheaper to by a second hand unit and use the old one for parts.

My questions is will my larger lawn deck (three blade) on the 5211 work on the 5212.5 (which currently has a two blade smaller deck). My guess is the attachments are interchangeable -- but not the engines.

Michael Taylor
July 2009