63/64 427 exhaust manifolds

[ToddK]

I have just received a set of early long cast 427 exhaust manifolds I bought off ebay. These are the first set I have seen up close in real life. I've noticed that on both manifolds, one of the upper bolt holes is a smaller diameter than the rest. Is this normal, and do I need a special set of bolts to fit these? Thanks.

[cammerfe]

I've owned, and used, over the years, several sets of the long---'63-'64---exhaust manifolds. I started with the ones that came on my '64 Custom 'R' delivered to me in Feb of '64. My last set was on my '63 F-100 ICB/390 PI when I got it in 1989. I have never noticed a difference in the diameter of one bolt hole, and never used a single special bolt. When I put the truck back together the last time, I simply got a set of the extra long stainless header bolts. They worked great!

KS

[thatdarncat]

Hawkrod's reply on the FE forum was correct - there is usually one hole with a close tolerance and the rest are looser fit. If I can I'll post a photo later this week of one of my manifolds - it's the same. Shouldn't require any special bolts.

[ToddK]

Thanks guys, I saw the replies on the FE forum. I'll definitely be checking the manifold face for straightness before I install them. It doesn't look like they had been drilled or welded, but wanted to make sure.

[thatdarncat]

Here's a photo. I checked quite a few Ford manifolds and they were all the same - one close tolerance hole on each.

[67GT500]

I always thought the small hole was the first bolt that was installed, which then centered the remaining holes..