What size bolt are 340 header size.

MilesnMiles · Post by **MilesnMiles** » Wed Jun 24, 15 10:01 pm

Just read that two types exist which is news to me. Can anyone tell me what I Need to order? I only need 3 of em

Pete · Post by **Pete** » Wed Jun 24, 15 11:50 pm

I thought the thread size was 3/8 UNC, you can get different head sizes ( 3/8 spanner or 7/16 spanner or even Cap Bolt)........

MilesnMiles · Post by **MilesnMiles** » Thu Jun 25, 15 7:40 am

Thanks Pete, I was confused by an ebay ad that had two sizes. I'll check back as it my have been head of bolt size rather than the thread in the block

http://www.ebay.co.uk/itm/MOPAR-273-360 ... 235317ec0e

Seems to indicate two different thread sizes which is news to me

Blue · Post by **Blue** » Thu Jun 25, 15 8:28 am

Are you sure you can get a spanner on a full size hex head? Most header bolts have a reduced size head so you use a smaller spanner for accessability in the tight space available.

autofetish · Post by **autofetish** » Thu Jun 25, 15 9:00 am

Blue wrote:Are you sure you can get a spanner on a full size hex head? Most header bolts have a reduced size head so you use a smaller spanner for accessability in the tight space available.

what he said

im using a cheap set of missmatch hooker headers and had to use studs and nuts for 4 of the bolts

MilesnMiles · Post by **MilesnMiles** » Thu Jun 25, 15 9:03 am

No, I have really good access. All tubes have clearance for bolt heads. I've checked them all. TTI quality, there. I also have spark plug boot clearance as well.
Which is nice.

Carl · Post by **Carl** » Thu Jun 25, 15 7:26 pm

3/8 12 point bolts I'm using

MilesnMiles · Post by **MilesnMiles** » Thu Jun 25, 15 8:26 pm

Thanks Carl, got some on the bay today.

Gareth · Post by **Gareth** » Sun Jun 28, 15 2:22 pm

What length bolts are you using Miles ? Those TTI headers have pretty thick flanges on them.

MilesnMiles · Post by **MilesnMiles** » Sun Jun 28, 15 6:13 pm

Gareth, 1" thread. However, I do need a bolt with a small head as the final hole on cylinder 7 won't take a normal bolt and I can't get an Allen key in to use an Allen bolt