Hi guys, I just bought a 78 ford 3/4 ton 4x4. The 400 engine is bad. (rod knocking) I know a guy that has a 400 that runs good but the roll pin sheared of the distributer gear. He went in and replaced the timing chain and gears. Bought a new whole new distributer and drove it a few miles, went dead. He pulled the distributer roll pin was sheared again. I would like to fix this thing and put it in mine. He's just giving it away. He's putting a 460 in his. Any ideas what would be causing this? This is my first ford. I really like it so far.
Shaun:confused:

seized oil pump?

Sounds like an oil pump.

I have a 428 Cj with a high volum oil pump that did the same thing. If the oil pump has been change to a high pressure or high volum it also can cause this. The way I cured it was to go to a after market oil pump drive shaft one made of cromoly round stock with the hex cut at both ends this stops any flex. I also drilled out the roll pin to the next size and installed a double roll pin. This completely cured the problem going on 10 years.
Leadmic

Yup, thats good advice. This isn't terribly uncommon, at least with the 385 class. Most guys just throw in the double roll pin and problem solved. Seem to see it more with the high pressure pumps vs the high volume.

I know after the pin sheered off the first time. He replaced the oil pump along with the timing chain and gears. I'll have to ask him if he used a high pressure, high volume, or standard oil pump. Thank you for fast info guys!

There is another possible issue at hand as well.

These engines have a tendancy if still equipped with a OEM oil pump pick up screen, to suck a hunk of dried up broken off valve stem seal into the oil pump...I don't care what ya do with roll pins this will wreak havok with the roll pins. Specially after you tear off the pan....drive it a few months and all is well and POW it does it again....it doesn't take much size in the debri to get this result....

NoRM