Personally.. I'm not a Ford Fan. (I like Chevy and Chrysler)
We had a discussion recently about the Ford Triton V-10 (Biggest) v/s the Chevy Vortec 8100 (Also the biggest)
The spec sheet shows the two are matched, foot pound for foot pound in the toruqe department. This is what gets you moving. The ford had 15 more HP (this is what keeps you moving)
What the spec sheet did not make clear is this
The Ford engine is a 'High-Reving" engine (I get to expierence this when I drive my wife's car) this means it does not develop full power, either HP or Torque till it's wound out some, quite a bit in fact. With my wife's car (a Mercury) Acceleration does not kick in till about 10 MPH.
The Chevy engine however is a lower reving engine, This means it hits both peaks sooner on the RPM curve, which means better performance "off the line" and a longer engine life
At the top end, the difference between 335 and 350 HP is .. Well, less than 5% and anything less than 10% is basically nothing... So I never notice the slightly lower HP of my Vortec over the Triton
And a hundred thousand miles or two down the road... I may well notice the longer life
(By the way, short engine life is EXACTLY the reason I'm not a Ford Fan)
I'd pick the Ford V10 over the GM 6.0L Vortec any day. You are comparing a mid-sized GM engine against Ford's biggest gasser. The only fair comparison would be the V10 versus the 8.1L Vortec, which is a fine engine and every bit the equal of the Ford V10 (as John explains). The chassis you are looking at is no doubt available with the 8.1L engine and i would avoid getting the lesser-powered one unless there is a substantial $ savings and you are not one who cares about performance.
You need to be looking at are the chassis weight carrying capacities, the GVWR and GCWR, the unladen weight of the rig and the CCC (available cargo carrying capacity) of the motorhome. Make sure you have plenty of CCC, even if just using for weekend getaways. You can easily load 1000 lbs into an Rv and those of us who travel extensively usually consider 2000 lbs of CCC to be the minimum. I'm carrying about 3000 lbs in my rig.
Also compare transmissions. If either of the chassis is available with a 5 speed rather than 4 speed, opt for the 5 speed. It will perform much better on hills.
This is fantastic information to have, because we are shopping to purchase an RV. We like the Winnebago Sightseer, and the saleslady (who I thought was very knowledgable) told us that we could tow my Chevy Trailblazer without any problems. We are still doing the research though, because when you are a novice, anyone with an ounce of knowledge can tell you something and you believe. I know that once we put our John Hancock on those papers that's it!
IMHO it is very important not to take the salesmans word as gospel truth. Do the homework for yourself or ask here or have the salesperson show you the facts and figures using the GVWR for the Motorhome or truck. In other words see it in writing on documentation.