Mine were fouling out so I would change them and I would put in new autolites, after I put in NGKs it runs awesome. I did test all 4 sets of the autolites afterwords and 16 out of 32 were bad, I bought a 2nd new holley carb, rebuilt the factory distributor again bought a HEI distributor and ended up putting a Pertronix distributor on my rebuilt 460. When it was said and done I spent about $600 and 20 hours extra that I didn't need to.

 

So we figured out the popping the #4 cylinder intake valve had a bent pushrod, so we replaced it and runs great now

 

Good deal! Thanks for the update.

 

Please answer this for the no as mechanically advanced. By taking off the valve cover and looking at the push rod, in that short visible area you can see a bend in the rod? Is it that extreme? Or did you pull them all and look? Thanks