KD we bought a 1993 GBM 32' Pursuit on a 1992 Chevy P30 in 2007 for $8K and fixed it up starting with the chassis and a leaking roof (bad to buy a MH in the middle of a three month drought).
In 2011 we did an 8K mile trip to the Pacific Ocean hitting WY, ID, UT and AZ in the process so we got in a lot of mountain driving. It did well in the mountains.
Our P30 chassis handles and rides very well but it has 208 wheel base where some only had 190" WB and did not handle so well per some reports here.
Chevy 454's got the TBI system and 4 speed automatic 4L80-e transmission in 1991. 1990 and back had carbs instead of TBI (early form of fuel injection) but they are OK too.
It sounds like you have skills so I think old MH might work out for you. Ours was going to be a play house for the kids (they asked for the MH when nine) had I found the motor or transmission was in need of replacing but now 20K miles later both are still strong at 109K miles. The PO had replaced the transmission at 77K miles that helped me do the deal the night we looked at it.
Keep us posted on what you get. The Ford 460 engine of that era are good engines too. I am old enough for the 454 to have a cool ring to it. :)
If you need the 5000 hitch you may need to get a diesel rig. The gas units tend to have extended rear frames that carry hitches rated at 3500 because of the lighter weight frame extensions. Our P30 hitch is rated at 3500 I know. You might find towing 5000 pounds will eat an old transmission too.
Consider a newer gas chassis to get a 5000 hitch.