I have a 390 that I am going to rebuild soon and have located another set of heads with the 16 bolt exaust manifold pattern. The owner says they are from a 390 GT engine and are rebuilt. They look good and he wants $400. The heads are more money than I had planned on putting into the heads I have so it would add to the cost. Are these heads worth messing for $400 to gain any performance over plain 390 heads.

 

Are you sure they are 16 bolt heads and not 14? Ask the guy for a casting #.

The top head is a 16 bolt CJ head, second from the top is the 14 bolt GT head. AFAIK, 16 bolt heads were all CJ and 14 bolt were GT or regular intermediate car heads.

 

I have not looked at the heads close enough to get the numbers off of them. I'll get them and post them later. They do have the 16 bolt pattern on the exhaust the same as pictured on the top. So, these heads could be the CJ heads if someone hasn't added the extra bolt holes? Can the other bolt holes be added to the GT heads to appear factory?

 

Casting # is your best bet. A GT head can't be made to look like a CJ head. Check out the upper bolt holes, the CJ has them all in the same plane while the GT has the end ones lowered.

Also notice the height of the ports, the GT has lower ports compared to the CJ. Use the diagonal bolt holes as a reference. On the CJ the floor of the port lines up with the top of the bolt hole and on the GT the floor lines up with the bottom of the same bolt hole.

 

Thanks for the reply BB...I learned something today if know one else did?? LOL!! And I didnt even post the Question!! Cool.... -Russ

 

I have to admit I never noticed lower end bolt holes before. I'll look closer at the bolt pattern and get the casting numbers and I'll post them.