What size header bolts for a 72 340?

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fire_medic

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I am putting on new header gaskets and am not going to reuse the old bolts. Anybody know what thread size is and how long?
Thanks
 
But if yours fit like mine you will want to make sure that you are using small head bolts so that you can get a wrench on them. I used a few allen heads where they were really tight.
 
Thank you, yes it is pretty tight on a couple of them. Had a hard time getting to the Allen heads. It was a real pain. Took me over two hours to get them off. : (
Any tips or special tools that make it easier?
 
Buy specialty header bolts from jegs or summit, they have a smaller head than a regular bolt. They are not that much money and worth every penny you spend on them.
 
fire_medic said:
Thank you, yes it is pretty tight on a couple of them. Had a hard time getting to the Allen heads. It was a real pain. Took me over two hours to get them off. : (
Any tips or special tools that make it easier?
Click to expand...

There are a couple where it helps to put a small dent next to them, it's easier to get a wrench on.

But, look at the ones I posted, I used those and it was pretty straight forward. Put a dab of neverseize on them when you put them in.

Non hardening sealant on the front and rear ones as they go into water.
 
Bad Sport said:
I suggest these:

http://www.summitracing.com/parts/stg-8915/overview/make/chrysler

And these:

http://www.summitracing.com/parts/php-66037/overview/make/chrysler
Click to expand...

Ditto on denting the primary tubes. The only one I needed to was the #7 (rear driver's side) but I could tell I needed to before I installed them. I had a hard time putting a bolt in that hole when I tested it ahead of time. I'd suggest trying to scope the headers out closely BEFORE you're fighting them in the engine bay. I had a spare motor sitting that I test fit mine on but you don't even have to have another engine to test your wrenches for reach.
 
sireland67 said:
Those percy gaskets are really nice, I use them also, but have had good luck with these bolts.

http://www.summitracing.com/parts/arp-144-1102/overview/make/plymouth
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1967 'cuda said:
Ditto on denting the primary tubes. The only one I needed to was the #7 (rear driver's side) but I could tell I needed to before I installed them. I had a hard time putting a bolt in that hole when I tested it ahead of time. I'd suggest trying to scope the headers out closely BEFORE you're fighting them in the engine bay. I had a spare motor sitting that I test fit mine on but you don't even have to have another engine to test your wrenches for reach.
Click to expand...

I used those bolts and Remflex gaskets and didn't have to ding anything.
 
I use allen head ones for all but "those" hard ones (you know the ones), for which I use regular (hex head) bolts and it's easy to get an open-end wrench on. But for the frontmost and rearmost on each side, I put in studs. You can seal them up good (water passages), but also it makes install so much easier, especially if you're installing the engine yourself. Just wrestle each header into place, letting the studs hold it on, then start putting the bolts in. Makes a hard job much easier. I didn't have to dent anything on my headers, but then, every kind of header is different. The most recent ones I did were Hooker Super Comp.

The other maybe not-so-obvious advantage to using studs on the front and rear holes is that if you need to change header gaskets or whatever with the engine in place, having those studs there keeps the water in. I really like the Remflex gaskets.
 
I should have said, I buy all my header bolts from the hardware store. Can't get the gaskets there of course!
 
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