Before you go any farther, when was the last time the fuel filter was changed? We had a similar problem with our 2001 motorhome on the F53 chassis. Loss of power, especially when trying to climb hills, poor idle, etc., etc. I checked the maintenance records and found the last time I changed the fuel filter was nearly 60,000 miles earlier. I went to a parts house and picked one up. When I took the old one off it must have weighed close to 10 pounds. A quick test drive and everything was working great. No hesitation, plenty of power to climb hills, and no more rough idle.
If a fuel filter doesn't cure the problem you may need to remove the tank to access and replace the studs. Here's a link to removing the tank on a 1996 F53 chassis.
http://www.irv2.com/forums/f23/f-53-fuel-pump-change-pictures-75723.htmlThe pump is different, but the tank removal and installation should be the same. If at all possible I would drain the tank. At 6.3 pounds per gallon a full tank (75 gallons) will weigh well over 300 lbs.
