Tim Full Force, posting on this thread is pointless. The entire thread is based on someone's butt hurt because someone said they could improve afrs exhaust port.

How dare you even mention guide clearance could be a possible issue with one of their out of the box heads. I bet it was because you didn't run 5w40 oil.

Yea I know I am on to 2 causes both not my fault....

As far as plug shown, I'm sorry not timing that shows NOT LEAN

Correct it shows pig rich.

Detonation was not the issue....

I put valve in oven at 400 degrees put in guide was very snug, yes a hillbilly test but makes ya go hmmmmmm

Now put the head in the oven and give it a try.

Valve runs hotter then the head especially in lake water in may....

I agree. But the head isn't going to be room temperature. So, if your going to waist your time putting the valve in the oven minus well go all the way and throw the head in also.

Tim, I did the very same thing last summer first time out. Only difference was 1000 more rpm it was detonation. My head was ten times worse. I ended up replacing valve seats in the other side of the motor. 2 Pistons bunch of valves and seats some welding and a bunch of grinding it was back together. Mine also hung the lifter in the bore. Polished the lifter re-used. Once I got it back in the boat I stopped paying attention to the wideband and tuned it from the plugs. Once I got the proper tune-up/ temperatures in the motor. You could push it wide open and go to sleep.

Exhaust valve 100 times more common to seize than intake...or more.

You ever find out what caused the 1/4" or more clearance from dist to dist pad on intake ? Reason for asking I never heard if you checked intake port flange to see if a bunch of material was milled off from last build....or deck was cut considerably....or ?

You ever check lifter bore to lifter clearance ?

How did you determine pushrod length ? Any pics of the rockers installed ?

Guide could be trashed now from the trama anyway. So, I don't think checking the guide vs valve right now would show accurate results.