Do I have the correct head bolts?
Thread Starter
Racer
Joined: May 2000
Posts: 322
Likes: 1
From: Manchester TN
Do I have the correct head bolts?
I got my new head bolts at the dealership and they are different from what I took off. Instead of having a 5/8" heads with washers, these have 1/2" heads with built in flanges. Length a thread are identical. They were ordered by part number for a 1991 Corvette L98. Does anyone forsee a problem with using these bolts? As always, any help is greatly appreciated.
Burning Brakes
Joined: Feb 2000
Posts: 871
Likes: 1
From: Westland MI.
Re: Do I have the correct head bolts? (torque91)
The only concern I would have is the missing washers. The washer is there to act as a barrier between the soft aluminum head, and the hard bolt head. Imagine torqueing that bolt down on the head. It will be turning on the head possibly galling the surface. A washer in between will sit still on the head, and let the bolt spin freely to it's torque setting.
Might want to have the dealership doublecheck the P/Ns.
Might want to have the dealership doublecheck the P/Ns.
Thread Starter
Racer
Joined: May 2000
Posts: 322
Likes: 1
From: Manchester TN
Re: Do I have the correct head bolts? (scorp508)
These are from GM. The part numbers match that of the listing in the computer at the dealership. They were listed specifically as 1991 Corvette L98. The bolt head marking has an H encircled by a C. I'll have pics that compare the two bolts as soon as I get them downloaded.
Thread Starter
Racer
Joined: May 2000
Posts: 322
Likes: 1
From: Manchester TN
Re: Do I have the correct head bolts? (torque91)
Here is a picture of the two bolts;top=old,bottom=new:
Does anyone see any danger in using the old bolts? I have replaced the head gaskets in the past and used these original bolts. The car has 190,000 miles. I am not sure how the high milage would affect the bolts. I have always heard it is a good idea to use new head bolts on a rebuild.
[Modified by torque91, 4:01 PM 6/12/2003]
Does anyone see any danger in using the old bolts? I have replaced the head gaskets in the past and used these original bolts. The car has 190,000 miles. I am not sure how the high milage would affect the bolts. I have always heard it is a good idea to use new head bolts on a rebuild.
[Modified by torque91, 4:01 PM 6/12/2003]
Drifting
Joined: May 2002
Posts: 1,581
Likes: 2
From: The Motor City
Re: Do I have the correct head bolts? (torque91)
torque91,
I bought the same set when I reinstalled the heads on my '89 L98. I was concerned about the missing washers too. My machine shop told me that I didn't need them - they said that all new GM engines (with and without aluminum heads) have these bolts and they don't have washers. But, I personally didn't like putting them down without hardened washers so I ordered up a set from ARP. A set of hardened washers from GM would have probably been cheaper, but hind-sight is 20/20.
My advice: Get the hardened washers. The peace of mind alone will make it worthwhile.
I bought the same set when I reinstalled the heads on my '89 L98. I was concerned about the missing washers too. My machine shop told me that I didn't need them - they said that all new GM engines (with and without aluminum heads) have these bolts and they don't have washers. But, I personally didn't like putting them down without hardened washers so I ordered up a set from ARP. A set of hardened washers from GM would have probably been cheaper, but hind-sight is 20/20.
My advice: Get the hardened washers. The peace of mind alone will make it worthwhile.
