I think I just might have found my problem...

Pedestal rockers get tightened to 25 ft/lbs, you don't adjust them by torque, you shim them.

 

the last thing i can think of is did you torque all the rocker bolts at the same time or did you rotate the motor to make sure the lifters were on the base circle of the cam before torquing that rocker bolt?

the other thing that is coming to mind is that you said when you first brought this thread back to life, you had said your have a miss. if they bolts have not backed off enough to let the rocker not open and close significantly, you will still have the miss problem.

 

I did pull the spark plugs and roll the motor around when I was torquing them.

And yes, I am sure this was not the source of my miss, now that I have checked the rockers. But as I pull the spark plugs when I torque them all down again, I hope to find my miss. Plug wire, plug, or whatever is causing it. I wanted to check the rockers first because of the failure the last time I got a miss like this. A miss from a walking rocker will do WAY more damage than an electrical gremlin miss.

 

You're running Gt40 heads which take pedistal mount rockers as shown in the first picture above, unless you've had the heads modified to accept studs. When torqueing the rocker bolt from 0 lash to 20 ft-lbs you should reach the torque spec within 1/2-to-1 turn of the torque wrench, IIRC. If you reach 20 ft-lbs before turning the wrench 1/2 turn you need longer pushrods. If it takes more than 1 turn to reach 20 ft-lb you need to shim the rocker stands. All adjustments are made with the lifter on the cam lobe base circle.

I ran those same rockers/bolts on my P heads for a lot of years and never had one come loose.

Edit: In the first picture above, the two rectangular pieces with holes in the center are the shims I mentioned. They are usually two different thicknesses. Sometimes you need em, sometimes you don't. Valve jobs, milled heads or blocks all have an effect.

 

Scooper, if you are sure you have a MIS, back up in your steps a bit ( not sure you may or may not have done this already ) you need to find out exactlly which cylinder is mis-firing, narrow it down to 1 hole and go from there. Like i said i'm not sure if you have done it yet or not, should be easy to find if the mis is present at idle.

 

Just me, but I've found that rolling the engine around to torque pesdestal rockers is a huge waste of my time. Bolt em down and go. Stud rockers ? Yes, Pedestal's ? No.

 

If you don't go through the proper torque procedure for each rocker how will you ever know if the preload is correct for each? I've had setups where only three or four rockers needed shimmed. If I'd just cranked them all down I would have never known.

 

I have already installed these 3 times before. They have torqued appropriately each time. And I don't think I needed any shims.

The only reason I checked these first was due to history of them coming loose, and I wanted to double-check them anyway.

So, even if I found the miss elsewhere, I would have still eventually come back to double check these.

 

Never saw the need to worry about it, on a stock rebuild. On my 331 ? Yea, I went thru the motions.