I love my Planet X dinos, but I never really cared for the FoC designed heads. When the wave 3 titanmaster heads were released, I was finally able to repaint and mod some new heads to fit the PX bodies of Slag and Swoop. Grimlock is actually an older mod I did using the Alternators Grimmy head with the visor painted red. All still transform as normal, so no issue there. I purposefully left the PX bodies unmodded so I still have the option to flip back to the original heads if I ever changed my mind. Actually got the idea to use Fangry for Slag from a prior custom from @Grimlockimus, so thanks for the inspiration!
Thanks, all! Neptune/Sludge's head is fine enough, and it doesn't really bother me enough to change it. Summanus/Snarl's head is pretty much perfect as is. I don't own their version of Paddles, but he has no other robot head to reference it with anyway.