Tick Tick Tick

These are the gaskets I use on both V8s, and wouldn't consider anything else:

https://www.summitracing.com/parts/sce-4036

Installed using a high temperature copper RTV, such as Permatex Ultra Copper, and fixed with these fasteners:

https://summitracing.com/int/parts/stg-8953

This combination has seen 45,000 miles on the Mustang, and 15,000 on my blue Hawk without a single leak of the smallest kind.  The usual problem is heat cycles in the header bolts loosening them, and once the gasket has let gas through you won't seal it again.  The copper gaskets can actually be re-used with fresh RTV if they go back in the same position, but they're better replaced really.  It's also worth double-checking the length of the header bolts required, as a thick header flange will require longer-than-stock header bolts.

Original cars used Fastenal black-oxide 12-point header bolts with internal-toothed lockwashers.  This is what my black car has, but you have to go round often with a socket checking them.  They work - just - with the SCE copper gaskets, but the Stage 8 fasteners are way superior.  That said, it's not such a big issue with cast iron headers on cast iron heads, but I'm going to guess you have neither of those...

R

@roger-king

Thanks for the speedy response Roger. I’ll get onto Summit now 👍. 

Have a great Christmas. 

Dave. 

Hi Dave,

Halfords sell the copper RTV sealant:

https://www.halfords.com/workshop-tools/garage-equipment/head-gasket-exhaust-repairs/loctite-5990-premium-silicone-copper-gasket-maker-sealant

I think that regardless of what gaskets, sealant or bolts you use, it is worth checking your header bolts every few hundred miles after fitting until they settle down, which they will. I've used ARP header bolts and after a couple of checks, they haven't moved since.

Paul

Thanks Paul. 

How messy is the RTV should the headers need to be removed for any reason in he future?

Thanks again. 

Dave. 

@woodward289

The whole point of using the Stage 8s is that it's physically impossible for them to move.  You shouldn't need to tighten them as the copper gasket conforms to the mating surfaces of the metal, and won't compress futher over time like a fibre or composite gasket will.  The Ultra Copper is an RTV - it sets, so you peel it off like any other RTV silicone sealer, but it is designed for header temperatures.  As with all sealants, you get what you pay for so if shopping at Halfords make sure it's Permatex, or 3M or similar.  Loctite should be fine. 

@roger-king

Thanks Roger. I understand the bolts don’t come undone. Have ordered some thanks.

I was simply asking about the RTV should the manifolds ever need to be removed in the future. 

Thanks both. 

Hope it all works OK!  As I said, that set up has been great on the Mustang and the Hawk.  The fastener locks are a bit fiddly but once you get used to them they're easy.  You'll need a pair of tinsnips to cut the aluminium locking plates, but if you get one wrong, keep it safe as it's bound to fit one of the other bolts.  Don't forget you can turn them over to lock at a different angle.  Shout if you get stuck - don't think you will.