according to the GRP website, 26mm front, 26mm rear and 30mm rear ellegis are the same compound...
saying that, i have noticed the rings in the foam are in different places when comparing 26mm front and rears of the same shore.. so maybe there is a slight handling difference, but I cant say for sure as I've never tried fronts on the rear....
Category: 1:10 DTM MOUSSE
Model: ANT 1:10 DTM-26 MOUSSE for fronts or
POST 1:10 DTM-26 MOUSSE for rears
Rim: MM.26 A RAGGI for the normal ellegi spoked rim
Brand-name: Ellegi Technics