That's one area where the OT-64 does have it better, the troop compartment is taller compared to just about every Soviet designed APC/IFV ever hahaha!
But Paul, I am a little envious of you getting to ride around in the BTR-60. I only ever saw them in military museums so they were all locked up and immobile
But speaking of the BTR series, the reason the OT-64 has such large rear doors is the designers disagreed with the idea of having the troops jump over the sides of the vehicle to exit it (like in the earlier, open-top BTR-60). They believed that the safest way for troops to debus near the enemy was out the back with the vehicle providing some cover and even some concealment.
And the OT-64 used a diesel engine because again, the designers didn't like the idea of a petrol engine and all that very flammable fuel.
I had a quick look around the net for photos of the interior and found the following two pages that have a photo each of the troop compartment: -
http://www.warwheels.net/OT64cApcTROWBRIDGE.html
http://www.warwheels.net/OT64R4commandNicholson.html
But then I found this Czech forum page on the vehicle,
http://forum.valka.cz/topic/view/125...POL-OT-64-SKOT
and it had probably the best photo to convey the troop compartment dimensions. This photo (Kenyan UN troops with G3 series rifles): -
