1978 GMC Tioga: worth $1995?

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A 1978 RV has a carbureted engine and will likely get about 6 MPG in perfect tune. Properly setting up a carburetor is becoming a lost art.

Fuel is a major expense when operating an RV. 1,000 miles at 6 MPG uses 166 gallons of gas. At $3 a gallon that's $500.

Go a few years newer and you'll see RVs with fuel injected engines, transmissions with an extra gear (OD) and lock-up torque converters that improve gas mileage by about a third, reducing your fuel cost by a like amount.
 
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Any RV over 20 years old is a money pit. If you are filthy rich then go for it or take two grand and flush it down the toilet to get it over with sooner.
 
Worth it to do what? Turn into a tailgate buggy, food truck, luxury motor coach, shag wagon? Cams don't go "flat", but timing chains can jump I guess. Could be any of a hundred different reasons and it would be sheer luck if that mill doesn't need some serious attention. But, if that's something you're OK with and have a very specific purpose and budget in mind for this thing then it could be just what you're looking for. As a drive-away camper you can't get away from it fast enough.

Mark B.
Albuquerque, NM
 
They sure do. I had it happen in a 1984 Chey van, 305 CI. There was a bad run of cams back then (lobes too soft). I had a couple of valves would only barely move because of flattened out cam lobes.

See here.

73, -Don- AA6GA/7 Reno, NV
It's a real problem in the classic car world, especially since they've taken the zinc out of most motor oils. Lots of zinc additives out there now to help prevent it.
 
On the roller cam issue, all 460 fords and pre 1996 GM truck engines including the 350) are flat tappet cam engines. I have (had) both these engines in RVs. I started running 1 oz. ZZDP in Mobile 1 synthetic in about 2000. Supposedly that’s around 1400 ppm zinc. No problems. Please excuse the thread hijack.
 
Depends on your use plans? Weekend warrior, 50 mile rides? That is a lot of rubber and hoses that are due to be aged out.. We had a 83 Class c similar for 10 years, 2000-2010. Very little money added outside of routine maintenance. Kept it mostly in-state and under 60 mph. Did have aged out tires at the end, still used it. Sold it for about what I paid, was a great deal.
 
Any old RV that runs and has working appliances is worth $2000, but know that you are buying into a lengthy series of repairs, many minor but likely some major ones too. You had best be a capable Do-it-yourself type becsue paying for shop repairs would quickly exceed the value of the RV. New tires & batteries will probably be your first expenditures. That acceleration issue could be as simple as a dirty fuel filter or fouled spark plugs, or maybe you are just expecting it to perform like a late-model. THAT ain't never gonna happen! This is a carbureted engine with a 3-speed transmission.
 
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