changed distributor and ignition module on 1978 f150 with 302 and truck started and ran fine. While driving truck died and found that whole distributor moved. And yes bolt was very tight on base of distributor. What would cause distributor to move?

 

Did distributor move or did cap move?

 

Is the bolted distributor actually holding the dizzy base securely? Regardless of how tight the bolt is?

It "looks" tight. Is it?

 

Was the distributor completely seated before you tightened the clamp?

 

the whole distributor moved. There were shavings where the distributor moved left by the bolt that secures distributor at base. Never seen this before.

 

yes the distributor was completely seated

 

yes it was tight. Left some shavings from distributor at base by the bolt. Everyone I have talked to cannot understand how that would happen. Thanks for the help

 

have you removed the cap to look inside? maybe something came apart and caused the shaft to bind up and move the distributor housing. maybe the shaft seized up inside the housing? try pulling the distributor out and make sure it moves freely.

 

HIO, please tell me your not using that rusting clamp on that beautiful engine.

 

Best advice is to pull the distributor back out and see what you find.

 

LOL. Of course not! You know me better than that!

That's a hot-linked image off the web.

 

Did the hold down bolt bottom out? Maybe check bolt length and chase threads.

If it was really clamped down and still moved, something is likely locked up/torn up inside the distributor or drive. Pull and inspect should tell.

 

Are you sure you have a 302 distributor?
I seem to recall that 351 distributors were a small bit longer than the 302. They would fit in place but would bind up because of the length and trash the drive gear.
There should be a number on the side of the distributor (it should have 12127 in it). Post the number and I'll see if I can ID the distributor.