351w header bolts

[mladen]

I'm at a point where I'm ready to install the headers (I have Gasn headers). I read a few threads about bolts. Standard options include ARP, Stage 8 (which, seems, are hard to use), and Percy's (which don't seem to be sold anymore, other than on eBay where authenticity can be questionable). Anything out there in terms of the latest and greats when it comes to the cutting-edge tech of bolts?

Gasket wise, BPE recommends FelPro Fiber perforated steel core, Percy MLS, Kooks MLS, and Copper, so will be looking for those to match my Gasn headers.

[Mike.Bray]

I used these 12 point header bolts and they worked great. https://www.summitracing.com/parts/arp-400-1209

I think the Remflex are the best gaskets. https://www.summitracing.com/parts/rfl-3083

[BrewCityCobra]

I'm at a point where I'm ready to install the headers (I have Gasn headers). I read a few threads about bolts. Standard options include ARP, Stage 8 (which, seems, are hard to use), and Percy's (which don't seem to be sold anymore, other than on eBay where authenticity can be questionable). Anything out there in terms of the latest and greats when it comes to the cutting-edge tech of bolts?

Gasket wise, BPE recommends FelPro Fiber perforated steel core, Percy MLS, Kooks MLS, and Copper, so will be looking for those to match my Gasn headers.

I used the Stage 8 with the GasN headers and didn't find them particularly hard to use. At least, no harder than what any other bolt would be given how tight the tolerances are in a few spots (e.g., the driver side). Attaching the "Wedges" and "Clips" is certainly tedious but I didn't find it particularly difficult. I just waited until I knew everything was in place so I didn't have to do multiple times. I also went with Ultra Copper and ditched the gaskets. I've only run the engine for about 10 minutes at this point but no leaks as of yet.

[rich grsc]

ARP header bolts, Ultra Copper, no gaskets. When I installed the bolts, I put a very small swipe of Ultra Copper on the threads, none ever loosened.

[mladen]

I used the Stage 8 with the GasN headers and didn't find them particularly hard to use. At least, no harder than what any other bolt would be given how tight the tolerances are in a few spots (e.g., the driver side). Attaching the "Wedges" and "Clips" is certainly tedious but I didn't find it particularly difficult. I just waited until I knew everything was in place so I didn't have to do multiple times. I also went with Ultra Copper and ditched the gaskets. I've only run the engine for about 10 minutes at this point but no leaks as of yet.

Which model of Stage 8 did you use? I'm eyeing these (https://www.summitracing.com/parts/stg-8913a) or these (https://www.summitracing.com/parts/stg-8933/make/ford). Not sure which tab shape would fit better. Chose the 1" long since the hole is 0.93" and the header flange is about 0.35"

[BrewCityCobra]

Which model of Stage 8 did you use? I'm eyeing these (https://www.summitracing.com/parts/stg-8913a) or these (https://www.summitracing.com/parts/stg-8933/make/ford). Not sure which tab shape would fit better. Chose the 1" long since the hole is 0.93" and the header flange is about 0.35"

So a quick confirmation - I mixed things up in my head a bit - I have the FFR headers with GasN Side-pipes. So not quite the same setup. The FFR header also has a 0.35" thick flange though so I suspect it is analogous.

That said, I went with Stage 8 - 8933. I found the "wedges" to be quite effective.

179640

179641

[Bob Cowan]

Stage 8's are pretty cool. But they can really be a PITA. You have to carefully fit each tab to it's bolt. If you need to remove the later, you have to be careful not to get them mixed up.

Percy's are good. But no longer made, so it's not a real viable option.

Standard small head header bolts work pretty well. Space is limited, though. 12 points are easier to tighten, but make sure to clearance the headers BEFORE installation.
https://i.imgur.com/fart39s.jpg


I like standard coated allen bolts. Work well. Fairly easy to tighten and install. You can buy a whole box of them from McMasters for the price of a set of Stage 8's. As said above, if you use silicone as a thread locker, they will rarely come loose.

I don't use header gaskets anymore. They rarely fit well. And the FFR headers have always had a significant mismatch, making gasket fit very difficult.

https://i.imgur.com/87FEEbu.jpg

I only use high temp copper based silicone sealant. Fits perfect every time, and will last for many years. Cheap, too.

https://i.imgur.com/DKCCFSN.jpg

[Jeff Kleiner]

No matter what bolts you use on the headers don't just run them in cold and forget about them...Best thing you can do is to go through several heat/cool cycles and retighten the bolts after each. With Stage 8 do not install the locking wedges until after you've done so.

Jeff

[mladen]

Thank you all! I'll definitely keep the heat cycles in mind

[BrewCityCobra]

So a quick confirmation - I mixed things up in my head a bit - I have the FFR headers with GasN Side-pipes. So not quite the same setup. The FFR header also has a 0.35" thick flange though so I suspect it is analogous.

That said, I went with Stage 8 - 8933. I found the "wedges" to be quite effective.

179640

179641

One other item I forgot to list, I did put the high-temp copper-based anti-seize on all of the bolts during install as well. Just for added protection against galling and seizing.

[Hoooper]

Best thing to do regardless of hardware is make sure you torque the bolts to the right spec. Ive never had any come loose when torqued properly. With header bolts sometimes they are tough to reach and get good leverage on so often you might think youre putting a lot more torque on it than you really are, but the torque wrench will fix that issue for you.

[Alec]

Best thing to do regardless of hardware is make sure you torque the bolts to the right spec. Ive never had any come loose when torqued properly. With header bolts sometimes they are tough to reach and get good leverage on so often you might think youre putting a lot more torque on it than you really are, but the torque wrench will fix that issue for you.

What is the recommended torque? 351w 427 with gas'n headers; 12pt ARP bolts.

[mladen]

On the forum I read 20 ft lb, BPE says 25.

[GFX2043mtu]

20 ft/lbs is plenty. Hardware depends on bolt spacing. If you go with the wider bolt spacing for a 351w the stage 8 locks will not hit the header tubes. Because of this they must be drilled and safety wired for them to work. If you use regular header bolts use a bell washer under the head to prevent them from backing out due to heat cycling and gasket compression from heat cycling. You will also want to measure them to ensure they don’t bottom out before the header is tight. If they are to long you need to grind them down. For gaskets I like mls gaskets all day long as they don’t compress when heat cycled. How ever the header must be flat or they will leak. For race cars I prefer just to use high temp rtv or you’ll want a stock in a header gasket company as you’ll use a lot of them. Just my two cents from a guy that’s done this a time or two.

[mladen]

If you go with the wider bolt spacing for a 351w the stage 8 locks will not hit the header tubes.

Can you say more about this? I don't quite follow (I'm super new to all this)

[Jim1855]

With some of the aftermarket heads the spacing between the individual cylinder header bolts is 3" rather than the traditional Ford spacing of 2". This is to allow larger primary tubes like 2" diameter rather than a reduced size and to not need to reduce the primary tube width.

AFR shows the exhaust ports for their head selections. The inner holes are at 2", the outers at 3". Not all of their heads have the wider spacing.
https://www.airflowresearch.com/220cc-sbf-competition-cylinder-head/

For my engine I use 3/8-16 Allen set screws as studs, 3/8 ID / 5/8 OD washers and 9/16" hex nuts in place of fancy and expensive header bolts. I also use SCE Pro Copper header gaskets.

Jim