A few weeks ago i finally got a timing light hooked up to my engine. It was a lil bit off so i set it to 6B. I ran great with no problems till a few days ago. It began to run a little bit rough,so i hook the light up to it and found out the timing mark was way off! the distributor is in the exact same spot that i left it in. I also noticed that durring the 5 minutes i had it idling, the headder tubes on cylinders 5 and 6 were glowing red! Any ideas?  

point type or electronic??????

if it is a point type you have to set the dwell to 28 degrees with the vacuum advances unplugged..

the vacuum advance on fords actually changes the gap slightly...as it goes through its arc of motion..  

the point type breaker plates also wear out...  the pivot in them wears... so the points move around too much... and end up in a different location every time you come off the throttle ....

the shaft bushing can also wear...

if you have electric ... see if the rotor snaps back to its stop when you twist it and release...     the point type dizzys sometimes have this problem,..

the rotor should snap back freely...  

Sounds like you skipped a tooth on the timing chain.  The tubes glowing red are a sign of the timing being retarded quite a bit.  Sound like you might be able to adjust this one out but if the parts are that worn, it'll jump again and next time probably won't start and run at all.  

Define "way off" - if it's a lot like 12-20+ degrees, then timing chain and you're lucky it did it that little bit.  Dwell will move it a little, not much.

Double check with the vacuum advice line off the dist.  

I dont know exactly how off it is, but it was before the marker.....i have an msd pro billit mechanical dist. with a 6a box...  

Then if the timing is moving around, you likely have mechanical problem.  It's possible there is a problem with the distributor, but my experience with MSD units makes that very unlikely.  

so i should check my timing chain right?  

unplug the ign coil..

take the dist cap off. leave the rotor on..

use a socket and a breaker bar on the big crank bolt .,..

using the breaker bar... bring the crank around to tdc 0...   then back it off while watching the dist rotor... when it starts to move.. stop...    

you will need to do this several times to see exactally how much play is in the timing chain...    less than 1/2 inch on the balancer is probably ok..   more than that and it is time for a check...

ps... all timing chains stretch. a ***  running with a tiny bit of slack reduces the amount of pressure on the cam and main bearings...  

ill give that a try...thanks for the help guys  

My brother has a '70 F100 with a stock 302, except for the Petronix ignition. He was living on the coast in Alabama and was complaining that after he changed his distributor the engine was running just a little rough and he couldnt get the carb or the timing to stay adjusted. He came up to see me and we checked it out. Turns out he somehow got the rotor shaft in the nutorious "180* degrees out" position. When the engine was supposed to be on #1 TDC it was around #5. Would also make a couple cylinders to run too hot, as evidenced by a couple of his plugs showing they were burning much hotter than the others. Years ago our dad and some of his old Ford mechanic buddys told us that was a pretty common thing to have happen. They had several stories of buying an old ford with a 302 or about any windsor engine and finding out the previous owner had gotten it timed wrong.