I think they might really be different pistons.
I’m no parts expert but there seems to be a different parts reference for the piston.
I compared the part numbers from the 2003 Toro Snow Commander (Model 38602) engine in my garage:
Engine family is 2L4X5-1415BA
Toro engine Model # 100 9536
Toro's web site references the R-Tek engines in the Snow Commander as:
084332-0130-E1 (on: 38600, 38601) piston assembly 801281
084333-0199-E1 (on: 38602, 38603) piston assembly 801281
Then I looked up some 3650 blowers from the same era:
084232-0121-E1 (on: 38517, 38537) piston assembly: 801279
084233-0198-E1 (on: 38518, 38538) piston assembly: 801279
084232-0121-E1 (on: 38440, 38441) pston assembly: 801279
084233-0198-E1 (on: 38445) piston assembly: 801279
This message was modified Mar 19, 2010 by Underdog