Have you checked your oil? Coolant in the oil is a good indicator

 

I may be able to help.......I read all your posts on what your describing as your miss fires.All the items you have replaced especially the plenum gaskets should eliminate mis fire codes.One thing we experienced at the dealership I worked at was the exhaust valve seats getting "egg-shaped" causing sparatic misfires.Most of these were on decent mileage 360's and would produce individual misfire codes.If you checked the valves and seats on the heads you probably wouldnt see it by the naked EYE alone.Your best bet may be to invest in a set of rebuilt heads and install them if you think the short block isnt damaged in any way.Good luck with the project and let us know what you find.

 

id take em off the motor and have them checked at a machine shop.They can do this for a good price.My local shop gets about 75$ to mag em to check for cracks.If they are cracked u can upgrade while there off and get some more power from the motor.
On another note(im sure u checked this)did u go over the wires and plugs good?After i buiklt my motor i chased misfire codes for 3 days and it all led back to a cracked sparkplug.Keep us up to date!!

 

Are cracking heads common on the 5.2L? My B250 has 111,700 miles, everything is okay now, but what about down the road?

 

There becoming a common sight on the magnum heads to be cracked.Alot of people i talked to only found out about the cracks after they were takin off,most didint even show a problem with the motor.

 

I would agree with neversatisfied and have them checked. I had cracked heads and warped valves causing cylinders with low compression but looked okay to the eye(except for one crack) and never leaked any water into the oil. They failed the pressure test at the shop and replaced them to solve the problem. While you've got your heads off check your piston walls for grooves going in the wrong direction or that are too deep to make sure you don't have ring problems as well, this would complicate the issue. Good luck.

 

You are 100% correct. I repulled the suspect head and took it to the shop. Sure enough a deep crack in #4 cylinder between the intake and exhaust valves. A smaller crack same spot in #8. They said that my head is not repairable. Dodge wants $551 for a new head and the best price for a reconditioned head is $250. I am trying to find a performance head at a reasonable price. Any ideas? :help:

 

jegs and summit have magnum heads new for 300$ each,not a bad price or the r/t heads for 450 each.aluminum for 600 each.depends on how much u want to spend really.I am going with the edelbrock aluminum magnum heads,700 each complete if they ever release them.If money is tight go for the cast iron magnum heads for 300 each,there new,not reconditioned.

 

Thanks neversatisfied..... I looked up the heads on Jegs. $309 for a complete cast Iron and $691 for a bare aluminum (uses larger valves and springs, so the complete head will cost over $900. While I'm sure the performance gain is decent for the aluminum, I think I'll stick with cast iron. Thanks so much for the tip.