Ive had this truck for a year and it just cannt get out of its owen way
Its a f900 10 wheeler dump truck with a 5speed trans direct/over/ under
which give you about 15speeds.Top speed is 55mph empty! 2500rpm
Ive done a tune up,plugs ,wires,points.And rebuilt the distributor--bad
bushing.timing is 10 degress befor tdc.truck runs good,starts everytime
gets 6-3 miles to a gallon.ive had enough and im going to drop a 3208t
and allison at in if this motor wont pull any better.ARG!!!!!
ANY SUGESTIONS!!!!!!

 

You might want to check @ see if the govenor is opening properly, also those old govenor HOLLYS were a real pain!!!!
they would not open completly. Most of the old gassers around here have 650 to 750 CFM aftermarket carbs on them.
Our old boom truck 534 5spd 4spd aux has a 750 EDELBROCK on it with no govenor that really woke the old girl up. Im not advocating that you do away with your govenor.
only that its probably the reason you not developing more power. Many that come thru our shop have had this problem.
If you do disconect the govenor make sure you watch your RPMS!!!! I hope this helps HOTWRENCH

 

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Interesting. All the 477/534s I've seen (only a few) had big Holley 4 barrels on them. I just figured that ws the stock carb!

 

I would concour with hotwrench on the governor causing a problem if it is a Holley. They operate on the principle that the throttle is springloaded open and when the governor cuts in it over rides this spring tension to close the throttle. The linkage to your footfeed only pulls the throttle closed so if there is any stickiness or binding you won't get full throttle. The vacuum secondaries can also be a source of a lack of power if they don't open. It might need a rebuild too if the metering block gaskets have dried up and shrunk. But these were tempermental carbs if everything wasen't right, switching to an aftermarket carb might be a solution if you're the only driver on the truck and have a tach that works. Check the advance mechanisms in the distributor too for proper movement. I have an old GMC tandem with a 478 V6 and 5x4 trans. I can push the old girl up to 75 without to much effort when it's empty at 17,000lbs and it only has a little 2bbl stromberg carb.

 

I had the same symptoms with my 1978 f800 dump truck with a 477. I adjusted the timing (with the vaccum to the distributor unhooked and plugged) and now it runs great; although I have not had a big load on it yet. Still only tops out at 55 mph though.

 

Allready disconected the vacum advance and adjusted the timing
Im going to replace the carburator.

 

I would like to know the year of the truck. Unfortunately, like the boxer that continued to fight long after his prime, the Super Duty V-8's had become pretty weak by the late-70's. One of the reasons they were dropped was due to the fact that the 534 had become not very much more powerful than the 429 Lima truck engines. The huge bore and combustion chamber design made for a dirty running engine, and Ford compensated with dual air pumps, retarded timing, and a host of other add-ons to try to clean it up.

 

It is a 1972 10-wheel dump truck.
With a 5-speed and a 4peed aux trans.

 

1972 is early enough that it should run good.