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Old March 20th, 2014, 12:55 AM
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GMCDAC GMCDAC is offline
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Location: Green Valley, east of Rapid City,SD
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Default Re: Blown head gasket vs. cracked block

Quote:
Originally Posted by Vern View Post
One of the comments I heard when asking around is that it's not worth getting the head worked on without replacing the rings, bearings, and getting the driveshaft machined? Sounds like I either need to just replace the gasket only and cross my fingers or go all out on a rebuild?
Hi Vern, a lot of mechanics claim that if a fresh head or heads are installed on a worn short block that it can cause the rings and possibly bearings to fail due to the increase in compression because of better sealing valves. I don't buy that, done it many times on race and street vehicles.

Just replacing a head gasket wouldn't change the compression and MIGHT solve your problem. Done that a lot of times too but it was usually obvious coolant was getting in a cylinder or leaking on the outside. It is definitely possible that the head gasket won't help. Just depends more about how much time you have to mess with it, not super expensive to try it.

Oh yeah, had to hit "edit"! I have no idea why you were told that the drive shaft needs machining while doing this work!!???

DAC
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Doug Crawford
Rapid City, SD

1970 GMC K5 Jimmy Mom drove 30 years
1972 GMC C2500 owned since 1979
1955 GMC 100 driver-project
2006 GMC Yukon Denali---wife's truck

Hope to have a '60 GMC Suburban again someday
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