460 emmision tube?

[robertj]

hey guys,new here question is: 85 f350 460,the air tubes on the back of the heads are held in with a bolt/clamp, is the big hole(top)threaded to put a bolt in? i think my older 76 460 was,but it may not have had the flat clamp either.If those are threaded what size?

[Diesel_Brad]

not treaded. they are pressed into the blocks that get bolted to the head

[robertj]

thank you for the help

[Sycostang67]

I just put a bypass cap on the center opening of that cross over tube.

[mercurycat]

I just used I believe a 1/2 " bolt. They have never leaked of fell out.
Hope this helps
Ken