Transformers questions by newbies, and not-so-newbies

[Ode to a Grasshopper]

Are the heads of Siege tetrajet Voyager Starscream and Earthrise Voyager Starscream cross-compatible? It looks like you should be able to do a headswap but I don't have either/both of them to compare.

Ta.

Just switching the heads from one balljoint to another.

I was wondering - if they ever release them in a way that anyone who isn't a North American scalper can get their hands on a set - that if you had the Earthrise Skywarp/Thundercracker set and any one of the Siege seeker/tetrajet molds, would you be able to switch out the screaming Skywarp head for a tetrajet head so you'd have a less goofy expression but with a slightly different headsculpt for variety's sake, as well as potentially mixing up the tetrajet faces a little (for example on Hotlink or one of the Rainmaker trio if you have/can get a hold of them too).

Not that it makes much difference for most of us right now what with that good old Australian TF distribution...

OK, so in case anyone else was wondering about/thinking of doing this, someone else asked-and-answered the question on TFW.

Siege and Earthrise Seeker headswaps are basically not possible without having to modify the toys, because the balljoints on both molds are different sizes. The Siege one is larger, so the Siege head on the Earthrise body will be loose, and the Earthrise head won't fit on the tetrajet neck/balljoint.

Bugger.