I've been fettling with this RV for a few years now as a long term project. Took a while but I've finally chased down and removed/replaced all of the broken bolts in the accessory brackets (5 total between the alternator and power steering pump) and the engine starts & revs fine. I have been running it around in my neighborhood the past couple of weekends now that I have the belts all aligned and tightened properly but the problem is, it won't accelerate over 35mph. I'm not trying to push it very hard but it just won't go any faster. Engine continues to rev, doesn't have any hanging idles or flat spots. Transmission fluid is still clean and red and is above the Fill line. Shifts are rough but they were rough in my other 6.2l RV and that got over 60mph.
Couple cromulent facts;
-33,000 miles on the engine
-Its got a Stanadyne fuel filter assembly up on top of the intake which is a hell of an upgrade from my original RV with the OEM setup
-Currently doesn't have an air filter, housing is there I just haven't bothered to put one in since I'm still troubleshooting the long list of electrical gremlins and not going anywhere in it yet
-Has a momentary switch for the GPs, sometimes it works sometimes it doesn't but either way the engine starts within seconds of cranking
-Exhaust is clear, no smoke whatsoever
-While working on the accessories I removed the fan and fan clutch and on the bench the fan spins ok but it feels a little "gummy". I can give it a twirl and it will spin around once but no further
-By the time I'm up to 30mph the trans has already shifted to 3rd. I seem to recall on my earlier RV the shift points were 15-18mph into 2nd then around 40mph into 3rd so this seems like its shifting way early

I am going to bring an infrared thermometer with me next time I drive it because while it brakes OK I want to check on the hubs and maybe I've got a brake that is dragging. I have Vol's I & II of the TDP maintenance & troubleshooting books but irritatingly I cannot find them.

Thanks for the help.