To make Prime Sergeant Kup REALLY different from Prime Ironhide: Mistransformation and a new head!

Edit: Final results a few posts below!
I have Generations Kup and the Upgrade head kit from I gear. The Cy-Gar head is used on the Gen mold and I have a spare head because the kit had two heads.
My question is, will that I-Gead head perfectly fit the TF Prime mold or should I hexpect some heavy modding?
I have Generations Kup and the Upgrade head kit from I gear. The Cy-Gar head is used on the Gen mold and I have a spare head because the kit had two heads.
My question is, will that I-Gead head perfectly fit the TF Prime mold or should I hexpect some heavy modding?