highway speeds/mileage?

[frogee]

I own a 86 international/bluebird/ 65 pass, conversion, 6.9l diesel auto, 95,000 miles, what kind of speed should i be able to get on the highway? i can only get about 65 on a good windy day ( wind behind) down hill, being towed by a yugo!, the "motor home" has tons of power in the city, motor is in great shape, good oil pressure, good compression knock, trans works great,
is there a speed limitter on these buses? or something?
also i was wondering what kind of mileage i should get on the highway?
also, here is a link to check out some pics of it as well as some atv's

http://home.comcast.net/~atvmisfits/home.html

[busone]

Your rear end gears will determine what speed you will get on the highway. If you are able to get up to 65 that is good. Most skoolies will top out at 50-55. If you change out the gears you could top out much higher.

[trx]

I know the 6.9's are known for their lack of power. Higher gears might work but that's if you are maxing out more on RPM and not power. Hopefully others with 6.9's will speak up if they've tried re-gearing. I'd like to do it with my bus (8.2T Detroit), mainly to drop the RPM's and gain a bit of speed. I can run 63 mph to the floor but I prefer the RPM's at 60 and it can hold 60 up most hills.