I've got a curious question. We know when the unit bonds the lungs are pulled back and more efficient ones are generated. The Smasher cells take up a large portion of the chest. Where do the pecs and ribs go? I would think the unit still needs the pectoral muscles to function in order to move the arms forward. Any thoughts?

The ribs I would think are still there, though expanded, enlarged, and probably placed further apart since the units always seem to be large than their hosts.

The chest muscle I would guess would probably be all that soft tissue you see when they open up their megasmashers. It would seem to be designed to flow around the megasmashers. Not to mention that they all seem to have large shoulders. That area could be packed with muscle to make for the chest area.

The unit just needs the host body for functionality....if the guyver is essentially the unit and host fused together to form a hybrid form, in lieu of chest muscles the unit could probably mimic or replace the function of the pectoral muscles with something of its own that is comparable to it.

i though that below the megasmasher where th muscles are shown at the side i woul think dat that was the place for ribs

Well in the fan fics you hear how the lungs are pushed out of the way to make room for when the megasmasher is about to charge and fire....this would indicate the the chest muscles are either fused to the armor in some way or they were replaced by a better version.