747 and 777 Domestic Models
 

I am interested in the differences between standard long-haul variants of 747 and 777 aircraft and the Domestic models primarily used in Japan.

Questions include, but not limited to:
How do the weights differ?
Do the engine ratings differ?
How are they operated - e.g. cruise altitudes, tankering, etc.?

To my knowledge, no 777 Domestic model has ever been offered. Boeing has also discontinued the 747 Domestic model.

However, some information regarding the 747 Domestic can be found at the Boeing website. Here's a link...

Boeing 747 stuff

Someone was telling me that a short range version of the 747 for Japanese domesting routes has the gear permanently down, ie., the gear has no retraction mechanism or gear doors. the flight are done all gear down. Is this true??

No it's not true, but the domestic models had beefed up gear and attachment points to take the high number of sectors that they do. Also the -400's do not have winglets on them as the sectors are too short for them to be an advantage.

...these are known as -400D's (D for "domestic"). Because of the lack of winglets, they look just like a -300 on the outside.

The 747-400D has no winglets due to the fact that they won't fit in the terminal with them. Japan asked for the permi gear down but Boeing declined. Any 747-400 can be converted to domestic for a huge fee. :D