VERY GOOD CATCH!!
Although the Simplicity FA did use a 2.5 horse Briggs I believe you are mistaken in your cross reference from the Wards Plow-Trac.
The "VB" could be the Simplicity equivalent to the Plow Trac.
I'm thinking you need a 7 horse Briggs "Model 19" to get the correct engine for your tractor. Your tractor is the flagship of the walk behind models having the two speed axle for 6 forward and two reverse speeds.
I have a Plow Trac with the Model 19 Briggs - there is a picture in the registry.
The last model featured on this page is the Simplicity version of what I'm thinking you have.
Now that I looked again I believe you might have the equivalent to the Simplicity "FC" that is second on that page. The FC had a Clinton 4 horsepower A-1200. No idea what the Wards version had for power.
????? Very well could have been a 4 horse Briggs.
The FC tranny looks slightly smaller and more closely resembles yours is why I think that may be the case. Hard to tell on from the pictures.
I thought only the 7 horse models had the hi/low axle until I looked more closely at that page.
Anyhow, VERY COOL machine and best of luck finding the correct engine!
Edited by Gtractor, April 14, 2014 - 06:31 AM.