Pontiac GTO Forum banner

1 - 4 of 4 Posts

·
Registered
Joined
·
15 Posts
Discussion Starter #1
Hey guys, does anybody know if the head gaskets for a 1966 389 are the same as a 1967 400?? I'll call around the parts shops, but if anyone knows right off hand. Thanks!
 

·
Super Moderator
Joined
·
5,744 Posts
Yep, oughta be fine. The heads themselves are different with respect to the angle between the valve stem centerline and the bore centerline, so you have to "do it right" in order to run 400 heads on a 389 (or vice versa), but for just the gaskets you should be golden.

Bear
 

·
Registered
Joined
·
15 Posts
Discussion Starter #3 (Edited)
Head gaskets

Cool, thanks Bear. I'm running 389 heads on 400 block, hopefully the guys got it right at the machine shop. I thought it was a 389 all the way when i had it re-built, but that was 15 years ago. I just found out it's a 400. It's been in storage for that long too. Driven about once a year and started about 6 times a year. I'm just getting serious about restoring, and want to get it mechanically sound first. Fixing my over-heating problem is the biggest problem i've got now. I'll get a new fan clutch, and check for head gasket leak.
 

·
64-67 Expert
Joined
·
8,561 Posts
Your overheating could be caused by corrosion behind the water pump at the divider plates, which in turn is caused by lack of use and lack of regular maintenance. The timing cover on these cars is made of aluminum, and the divider plates on '66 and earlier engines is also aluminum. The water pump and impeller are cast iron. Electrolysis is common in this area on cars that sit, and if it gets too bad, the water pump can not circulate coolant efficiently. If you've been changing your coolant every year or two, you're probably just fine, though.
 
1 - 4 of 4 Posts
Top