Pontiac GTO Forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
75 Posts
Discussion Starter #1
I pulled the heads off my 1974 350 due to two broken exhaust manifold bolts, which I needed to have removed by a machinist.

When I pulled the heads off, the threads on two of the head bolts got damage and will not cleanly install back in. Any suggestions on where to get individual head bolts? Seems it is relatively easy to find head bolts sold by the set. Would a new full set of ARP head bolts be the best way to go? The engine only has 28,000 miles on it and the heads have never been pulled off before.

Thanks.
 

·
Registered
Joined
·
1,611 Posts
No reason for a set of ARPs, just source the correct length nice used head bolts. Which position bolt do you need?

On a '74 Dport engine, the longest bolts (and two studded bolts) will be right under 3 3/4" measured under the head to the ends of the threads. The long front bolt on drivers side exhaust will have a threaded stud to attach neg battery cable. Same studded bolt was used above center exhaust port on pass side of block.
 

·
64-67 Expert
Joined
·
8,561 Posts
X2. Also, some ARP head bolts are a hair too long, which causes them to bottom out before the head can seal up with the block enough, causing head gasket failure.
 

·
Registered
Joined
·
75 Posts
Discussion Starter #4
Pinion,
It was the two lower, front bolts (#1 and 2 cylinders), the bolts NOT under the valve covers. 4" long, including the hex head, 3 3/4" under the head, shaft and threads only.
Thanks.
 

Attachments

·
Super Moderator
Joined
·
5,744 Posts
Depending on how they're damaged, you could also purchase the correct size die (as in tap and die set) and attempt to clean up the threads on the bolts you have. Just make sure that the bolt threads haven't been rounded/smoothed off to the point where they won't be fully gripping the threads in the block.

Bear
 

·
Registered
Joined
·
75 Posts
Discussion Starter #6
Depending on how they're damaged, you could also purchase the correct size die (as in tap and die set) and attempt to clean up the threads on the bolts you have. Just make sure that the bolt threads haven't been rounded/smoothed off to the point where they won't be fully gripping the threads in the block.

Bear
Thanks for the suggestion Bear.
 
1 - 6 of 6 Posts
Top