Hi gang Just-n-time here, Our 77 with a 351W in it has developed a proublem, the cam Drive gear has failed and destroyed the driven gear on the Dissy. I will have to replace the cam and I am looking for input.
Truck is set up like this, Edlebrock performer , 600cmf Holley, five speed with .79 final and 4.56 rear gears.
Looking for input on new bump stick, the block is an early model not a roller style.

 

Sent you a PM.

If you put a distributor with a cast gear into a late model 5.8 with a roller cam then that's why this happened, you need a steel drive gear on the dizzy to match the cam.

 

No not a late mod but rather an early one, the stick was replaced oh eight years back, I found the records but do not have info on type or lift, pehaps I will have it when I pull it out.

 

I'm more concerned with the fact that the bottom of the distributor shaft which drives the oil pump is busted out. Oil pump locked up maybe? Do you have a stock oil pump shaft in it (which would normally simply shear if the oil pump locked up) or an aftermarket hardened shaft?

 

No Dan that happend when I was trying to remove the gear from the shaft, the trouble is the teeth on the cam are worn down to a knife edge and the driven gear on the dissy are worn as if the two gears tried to ride each other.

 

I saw the chewed teeth on the distributor gear, just thought it might be related to the blown oil pump drive portion of the dist. shaft...but if you did that yourself from hammering on it, then obviously there's no correlation...

 

NO Dan there was no relation to the gear, I was the dummy who failed to check the end clearance before hammering
though I have another area to be corrected, the end plate for the cam is to thick. The came sprocket is rubbing it as in photos and a few of the came teeth.

 

Thought I would show one of the rear of the plate, too. No damage from the cam.

 

Maybe the distributor is too tight, causing the camshaft to be pulled forward by its gear, resulting in the thrust plate wear. The extra work required to turn a tight distributor could also wear out those gear teeth.

 

this is the second plate I have seen like this the three o two had a badly scared plate too, but it is only the cam gear side that is worn, the cam side is OK.