Thinking About a Class C

KD4UPL,

Thanks for the correction. For some reason I thought he was talking about a 1999. (scratching my head).

With "RARE" exception to the RV itself like a 1992-1995 Telstar motorhome, I would avoid an old Ford chassis that did not have the V10 engine and at least a 4-speed transmission.

For reference regarding fuel economy, our 2007 E350 with the V10 engine and the TorqShift 5-speed transmission of that era (MANY PICTURES HERE) averaged 10.5 mpg, a figure accurately logged and calculated upon returning from a ~5000 mile RV trip (not towing). 10.5 mpg is a whole lot better than a mere 6 mpg.....and there are other matters pertaining to performance, behavioral, available parts, and reliability.

I found a big difference between the 3 speed and 4 speed tranny. The 6 speed is much better. Ascending hills is easier and gas mpg is better.
Look into recurring exhaust manifold gaskets and fuel pump issues in that vintage. You might need to drop the fuel tank to access the pump . You might want to verify that if its important to you. At 32 years old, a lot can go wrong.

Like a 32 year old car, you are in for lots of RV system and mechanical repairs with parts from hard to find to none available. For short trips it might work out. Owner may be a friend but he/she also may have an unrealistic opinion of value.

An overdrive is a VERY expensive upgrade for a 1990 RV. $3500 for the unit plus a lot of install labor plus driveshaft modification machine shop work.

It doesn't have a V10. The OP said it was a 1990 model with a 460. The V10 wasn't even introduced until 1997.

I agree, a 3 speed is not going to do you any favors on fuel economy but there's an easy fix. You can install an aftermarket overdrive unit from Gear Vendors. This will not only give you lower RPM at cruiseing speed but it will essentially give you a 6 speed transmission, allowing you to select the straight thru or overdrive setting for each of the transmissions 3 gears.

Although I've never personally owned a 460, I have two friends that have.

They seemed to have two primary issues.

First, fuel economy, or lack thereof. Apparently the 460's love that gas, and 6 mpg was not uncommon for either of them.

Secondly was noise due to high RPM's at interstate speeds. At 70 mph the engine is quite noisy, and it's going through fuel like there's no tomorrow.

A newer V-10 version is what both of them ultimately bought, and both seem to be happy with their decision.

The problem with the Ford 460 is that while it is a good, durable engine, it's just so old now that, while any parts are still available, you won't be picking them up off the shelf at some auto part store in Podunk, Nowhere. Since most of us get RVs to travel, that's where most of the failures (fuel and water pumps, starters, alternators etc.) are going to happen. As Pianotuna points out, the early V-10s had a serious spark plug issue that was resolved by about 2004.
The nice thing about a V10 Class C is that while it has also been discontinued, it's still current enough (and shares many parts with the V8s and V6s) so that pretty much everything is a common stocked item at all the stores. I would have no problem getting a 460 truck as a daily driver at home but travelling with one of them would not be something I'd consider. You could end up having a trip really messed up waiting for something to be delivered. Don't know about you but here at home deliveries of all kinds have really gotten stretched out as of late.
Gas mileage isn't that much different from the V10 which is slightly better. We burn so much gas in RVs what's a mile or two? From what I hear, the new Ford V8 does manage to crack the 10 MPG barrier for a lot of drivers. I'll probably be looking for something with one of them next time.

27 feet is the perfect size for a class C, assuming the 176" wheel base.

1990 is going to have the spark plug issue where there were too few threads, if it is the v-10.