Header bolt size on 440s

[440DART1970]

I would like to know what the best size Header bolt to use on my 440 using schumacker Tri-Y headers and felpro gaskets

I have Mr Gasket 3/8-16 x 1'in long and they work but they seems to long.

I have heard stories about how the header bolts go into the water jackets on 440s and leak and i dont want to run into that problem.

what length header bolts should i use??

Thanks FABO!

 

[roccodart440]

on the stock heads some of them do go into the jackets and yes, they can leak. Make sure to use sealant.

Also, make sure they aren't too long for the blind holes.


I'm going to recommend you use Stage 8 Fasteners on your headers. They are the very best and can never loosen up.

 

[440DART1970]

Whats a blinde hole

 

[Marcohotrod]

a blind hole is one that has a solid bottom-does not go into a water jacket-so if the bolt is too long it can bottom out. with used iron it is good to clean threads with a tap, then screw all bolts in and see how deep they go

 

[440DART1970]

Which ones are blind holes

 

[SGBARRACUDA]

Take a pick that is 3-4 inches long and insert it in each hole, the ones that only allow it to travel 1-1 1/2" are blind hole , the ones that go in much farther are the ones that enter the water jacket. Do this and you will learn for yourself which ones to add sealant to the threads.

 

[SGBARRACUDA]

As stated above, it is a good idea to run a tap into each hole to clean out the threads. If you are running 3/8" flanges on those headers, than yes you need 1" UHL bolts. If they are cheaper headers with thinner flanges, you can use 7/8". I prefer to run the longest I can as long as they don't bottom out.

 

[famous bob]

As stated above, it is a good idea to run a tap into each hole to clean out the threads. If you are running 3/8" flanges on those headers, than yes you need 1" UHL bolts. If they are cheaper headers with thinner flanges, you can use 7/8". I prefer to run the longest I can as long as they don't bottom out.

I always use the longest bolts possible that won`t bottom out. especially on alum heads.

 

[Marcohotrod]

or studs

 

[WEBBY]

The end holes go into the water jackets, but run a tap in all the holes and clean them and use sealer on the end holes. Thanks Webby.

 

[oldkimmer]

On big blocks all header bolts go into water. Kim

 

[Marcohotrod]

if you have room to slide the headers on and off-studs!