That can't be Rosanna?  Thers always somethin... Last time I saw her she was purrrrin like a kitten!

Ouch !!! 
Hope it goes together with no snags, will you be replacing all the valve springs?

If that valve is the only damage from this failure, I think that you're lucky.  

Kinda lucky I guess.
Maybe. 
Who'd a thunk that sitting for 20 years then driving for 40,000 miles would fatigue the valve springs THAT badly? You know how many 5.0's have been abused, then sat, then abused more without sucking a valve? Those 10* valve locks probably should have held up. 
Arguable at best. 
 

I don't know, It looks like those scratches in that one piston will cause a reduction in compression ratio to me.

I got you beat rpm. Mine has no engine trans or wiring . And yet I am still planning to complete it by the bash….

Will probably see yall in the wife’s expedition lmao

I thought all the canted valve engines were clevelands!

Be sure your valve stems are correct length for the rockers you are using.

Steve69 wrote:

Good Luck to you!

 
Thanks Steve. Gonna need it. Yesterday I found 4 bad roller rocker tips. Guess I should have checked them a week or three ago.

What all full roller rockers are y'all using and happy with?

I have those in my 331 but 3/8” studs.

And the flight continues. I keep finding more things that need addressed and fixed. So in an effort to make the Bash, I pulled the 393, my bro Paul is delivering a fresh rebuilt 5.0 roller from Fresno for installation into Roseanne. What a brother, eh? I'll rebuild the 393 after the Bash, with new rockers, poly locks, valve springs, new valve locks/keepers, new spring shims, 1 new valve, 2 new bronze valve guides, new rings and cylinder honing, a valve job, and whatever else I forgot or comes up.

Hey, at least I didn't break a crank 1,300 miles from home. I dropped the valve one mile from my house. It could've been worse, much worse.

Good eyes there Terry. Following my brother's lead I swapped out my points ignition to electronic last year. That piece is a GM HEI 4 pin module mounted to a heat sink. I used a 1970 Motocraft distributor housing and swapped out the guts for Duraspark, and used a 1990 5.0 coil. The Delphi module is much smaller, one third the cost, and has less complaints than the Motocraft ignition module.

Just yesterday I told a buddy that I should have gone with the Trick Flow heads, which he has on his 408W stroker. I think having the proper valve spring pressure is the cure.  Since my valve springs were way down on pressure, I think they allowed the locks to come loose. Many of the hardened valve spring shims were beat to hell. My AFR heads came with 10° locks and retainers. Some good builders recommend the Manley Super 7 Degree Valve Locks.

Where are you on your repaint project on your original owner 69 Mach 1?

So, other than going from V belt to serpentine and swapping to a pass side water pump inlet and modding all your fixtures for accessories to work on the shorter 5.0, pretty straightforward eh?