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Discussion Starter #21
I will be going through the springs once I get my replacement BGE 6.4L heads. I don't believe the spring failed because the damage shows it broke on the upstroke aka it was bent upwards. Looking at the piston, the impressions show it smacked the valve flat and then shoved the valve into the head when the valve broke. I think the valve itself may have been damaged and over time failed. When going through my N2MB WOT box, I found a burnt pin on the main connector. Makes me think that this is the reason why I had the failure. I'll be taking this system off. The springs were PAC 1211x springs which was plenty of spring to handle that cam.

Here is a pic of cylinder #5.
1000075
 

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Discussion Starter #22
Got the Challenger back up and running Monday. Ended up replacing springs, keepers, retainers, seats, valve guides, and valve seals on a set of used BGE 6.4l heads. I went with PSI 1511 springs this time around instead of PAC 1211x. I also added the Stanke tie bar and collar system to stabilize the rocker system better. Granted I don't hit 7k RPM much, but I have done it in the past and wanted the extra insurance with the Stanke system. As much as I wanted to, I didn't stroke the engine. I did put in MMX's 392 Hemi 2618 Forged Mahle pistons and Molner rods kits with upgraded/coated bearings. The block didn't need much work but did get hot tanked and honed. The cylinder walls showed almost no wear, even after 57k miles. Rings were gapped to .028 for a future supercharger. I had an engine shop take care of putting the engine together, but I installed the engine in my driveway. Rings sealed after about 60 miles of driving and am now breaking in the engine. So far, everything is running well, but I still hold my breath when I crank the engine lol.
 
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Discussion Starter #23
And for you shade tree mechanics, I can't tell you how valuable a Quickjack lift is for vehicle repairs. I went ahead and bought one to do this job and it was worth it's weight in gold. Being able to lift and lower the car at the push of a button was invaluable removing and replacing the engine.
 
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