Dropping a bolt in the motor sucks but I don't think that is the cause of your knock. Most likely the bolt is lying in the bottom of the oil pan now, or the lifter valley area. I agree it sounds like a rod bearing to me. If it isn't too much of a knock you may be able to go a quite awhile with it like it is.

the bolt has been removed, the thought was that the bolt caused the damage that is making the knock

how long do yall think I have, I really cannot afford a rebuild right now

this couldn't be something simple like a dieing oil pump?

I have no smoke at all and no knock but at startup

couldn't the Lucas just make the oil stay in the head longer so when I start it up it is not dry and therefor not knock?

IMHO the upper is not the problem.Lucas is making the oil thicker temporarily and compensating for the worn bearing in the lower end sort of like a cushion.My guess is if you keep changing the oil (mabey to a thicker oil)when the knock re appears you might be able to run for some time.But do not get on it EVER just putt.Call youself " Lightfoot " from now until you get the motor work done.

You may not need an entire rebuild at this time. Drop the pan and check the crank journals. From your description of the problem at this time, there's a very good chance that a main & rod bearing replacement could keep you on the road for some time to come. If there's any marks on the crank that can't be removed with fine emory cloth, then it may be too late. But from what you've said, I think maybe not.

You now have a clearenced engine, good for more HP. Being serious now, I've had a few daily drivers that knocked on start up in the summer and were mostly quite in the winter. I didn't baby them and they died much later from other causes. Forget the RXs in a can and run heavier oil, the only oil my fleet see's is 15-40 Mobile Delvac (more anti-wear additives). Just a couple of pennies from an old man.

Exactly what I was going to recommend. You can cheat it from underneath and just do rod bearings. That wouldn't cost much in time or money and could possible buy you a lot more time on the road. I did this to my father's blazer and it's still doing well....and don't use fram filters.

how does this bolt get pass the lifter valley . And into the intake port of the head, is it a magic bolt