About Those Magnum Head Cracks:

[4woody]

Would you need to remove the heads to see from the chamber side, or would it typically crack through and be visible from the rocker side?

Anybody got a pic or two of a cracked one?

 

[toolmanmike]

They usually crack between the valve seats in the combustion chamber. Mike

 

[1wild&crazyguy]

mine have all been scraped, I learned early not to bother with'em...

but yeah, into the exhaust valve seats/chamber edge/plug boss etc...

 

[toolmanmike]

I have a nice pair with Mopar springs, retainers, keepers, and seals.

 

[moper]

The majority of factory heads will show cracks. Of that, about 40% of those actually have any problem associated with the cracks. On some they dont crack, some crack and never reach the cooling jackets, and some reach the jackets and make a problem. The best bet now is to get a set of EQ Magnums. Assembled and ready to run they cost less than re-doing a set of factory ones, assuming you get a set of good ones.

 

[4woody]

Thanks for the responses.

I was offered a '93 (I think) 5.9 Magnum, but by the time I put a carb intake, carb, and (maybe) heads on it I guess it might not be worth it, even for a mellow cruiser like myself.

Did Magnums get better in the later vintages?

 

[moper]

Nope. But a 5.9 core is still a good base. Getting more popular all the time, especially with the hydraulic roller cam in them.

 

[the wall]

mine had cracks both heads one cracked into coolant the other across the exaust seat causing the check engine light to come on and tell me miss fire #5 so im not sure about only 40% have real issues. im at 100% right now. dont know about the eq magnums but might be something good to look into

 

[dgc333]

FWIW, my son was the service manager at the local Dodge dealer (they lost the franchise last year). Anyway, I asked him about all the talk on the Internet about cracked magnum heads. His response was he couldn't ever recall having replace any heads due to cracking.

That doesn't mean there are no cracks but would indicate that they don't cause issues.

 

[moper]

Yeah, It's been a while but I was asst. manager in a Dodge parts dept in the mid 90s. It was rare there was a problem with them, but you could almost always see cracks without magging.