Ed- be sure to do some W/B calcs before opting for the extension. Moving a 55# prop forward by an inch and a half is significant, and will amplify the negative impact of polar mass on handling and spin recovery. Could be fine, just know before you go, especially considering that you have to do some cowling work anyway. You should be able to use your old W/B data to predict CG impact of new installation pretty closely.
I’m grateful to Hartzell for having made a custom hub just for Vans with a built-in 1” extension for the composite CS. That bolts right on with the standard cowl with no mods.- Otis
Built Monnett Moni
Frmr Test Pilot/Author CAFE APR's:
RV-8A, S-7C, Europa, Glastar.
-2019 VAF donation!!-
"RV-Fun is inversely proportional to RV-Weight!"