403 compared to 455?

[Bob Dunahugh]

There's about 10 to 15 hp/torque between the two as I recall. I have a 78 Royale 403. They're the heaviest at 12,000 lbs. My GVW is at 24,000 lbs when I'm pulling my enclosed trailer with a car in it. But I'm doing it with a 3:70 FD. Over all condition of a GMC. Or any motorhome is number one. Replacing all the seats/cushions will cost $3,000 now days. The frig, roof A/C, cooktop, and furnace can total $3,500. 16 inch Aluminum rims with tires,$3,200, engine $8,000, and trans $3,000. If an owner was big into maintenance. And is attune to it's performance. That should be a dependable GMC. Some owners do their maintenance on a crises schedule. They fix it when something breaks only. These owners tend to lack mechanical skills. Devil's in the details. Bob Dunahugh