zakt,
A '73 and up F350 will have front disc brakes. I believe they were an option before '73, but that those are the less desirable single piston calipers. Maybe somebody can help with that. I don't know about hydroboost, in fact I'm not even sure what it is.
I think that to run disc/disc you would need a master from from something newer than a '95. The '95 was disc/drum. As I understand it, you need to move more brake fluid for disc than drum brakes. That's why the disc/drum master has two different size chambers. What's your plan for the rear discs? Are you gonna use a later Sterling 10.5 axle?
MotorDog,
I am no expert, but I believe that everything but the springs should be the same. The different GVW may also be due to different rear springs. Do both trucks have the rear helper springs that look like this?
![Image](http://i115.photobucket.com/albums/n298/flatbedford/helpersprings/helpersprings008.jpg)
Or, do they have the same number of leaves? That may be the only difference. The different GVW may also be because of the disc brakes? My DRW F350 has a MGW of only 8300. It didn't have the helpers. Another member here had a '72 F350 DRW with the helpers and it had a 10,000 GVW. Funny thing is that my '00 F250 SRW has a 8800 GVW, 500 more than my DRW F350.
![Don't know :dk:](./images/smilies/icon_dontknow.gif)