I am bolting up my tri-y headers on my 66 mustang. It has the stock heads with the thermactor ports. My issue is every bolt hits the backside of each primary tube, so I can not thread the bolt in. I was wondering if you guys have run into the same issue and how you guys clearanced the back of each primary tube or went with different header bolts.

Thanks for the help guys.

 

I changed my heads out on my 66 to avoid the air pump. Try using hex bolts, or remove your air pump. you can buy the plugs for about $5 a piece, or use plugs you can buy at any hardware store with anti-sieze. you probably not gonna get around the prob unless you grind the header flange or plug the ports. Any one else have any ideas?

 

I have to put most of the bolts in the header flange before tightening anything down. I'll start one or two to line everything up, then pop the bolts in the holes while there's still plenty of clearance.

 

Yep, pull the flange away from the head as far as you can and still get a bolt threaded 2-3 turns, don't push it up to the head, let the bolts pull it to the head.

I think it works best without the gasket, start the 2 end bolts, pull the flange back, cut the ends of the gasket so the bolt holes are slots that go down to the bottom of the gasket, slide the gasket in and proceed with the bolting procedure from above.

 

Am I reading this as a case where Allen headed bolts might be a benefit?

 

thanks guys. I will give that a try when I get down to my house in a week.

 

I never liked that idea. Might work ok the first time, but what about the third or fourth time when the bolts are soft and round off easily? No, I like my ARP hex bolts.