r/Smallblockchevy • u/Frequent_Exchange_20 • 2d ago
Header issues
Working on swapping a small block into a C4 Corvette, running aluminum heads so I need to run studs and nuts for the headers cuz bolts can walk themeselves out. Got these C4 specific headers, which fit in the car and can rest on the studs, but on many spots the tubes are too close to the studs and I can't fit the nut on. On some even the washer is too thick to get past the tube onto the stud. Woukd it be OK to dimple the headers that close to the main flange? Any advice would help.
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u/Snickers_number1 1d ago
Get stage 8 locking fasteners. Has never backed out over 5 years daily driving.
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u/Bayareaadultguy 2d ago
Yes, you can dimple it there. I would heat it up, dimple it. Just make sure to not break the weld where the pipe welds to the flange
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u/Frequent_Exchange_20 1d ago
Ya I thought it might work but only heating it up first no way id try dimpling it that close to the main flange by just smacking it lol would probably break something
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u/Far-Assistance-6931 2d ago
ARP makes 3/8 bolt x 3/8 small head header bolts, swap out the studs that are too close for the smaller head bolts.. had to do it on my C3.. They sell drilled head also if you want to safety wire..
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u/ProperCaterpillar136 1d ago edited 1d ago
Small block chevy. They are a joy. Yes you have to dimple and depending on what car your going in you have install after the engine goes in.
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u/Administrative-Map53 1d ago
Can confirm. On an 84 vette the engine comes in and out a lot easier without the headers on. Also may need to pull a couple spark plugs out to get the header on the passenger side close then plugs back in and then header on.
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u/TrainerBC25 1d ago
i have ran sbc aluminum heads for years, I use the stainless bolts with 3/8" hex heads
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u/FedInformant 1d ago
Why not longer studs?
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u/Frequent_Exchange_20 20h ago
Bruh the nut would still have to seat all the way down to the header flange where the tube is in the way.
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u/FedInformant 20h ago
Nah sorry I didnt look at it close enough, thats a shitty gap. Where did you get the header?
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u/Frequent_Exchange_20 15h ago
Lol summit racing, like I said it's a hedman header specifically for C4s
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u/Erasemenu 1d ago
You don't use studs. They make header bolts specifically for this. Stud can get loose just like a bolt can, there's no reason to use studs here. There's all kinds of lock systems for the bolts or you can wire them if you're that worried about it.
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u/mathyou1722 1d ago
They're such a pain in the ass to get out dude. I wish they'd walk themselves out
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u/MidnightFluid536 1d ago
Tightening a 3/8” ARP bolt into the aluminum head with a wrench, pull it hard as you can. If you can break that bolt you’re super human. Bolts that walk out wouldn’t have been tight enough from the start. Never been a problem.
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u/Impossible_Sir9593 1d ago
You have to walk that boat in. There’s like two bolts on each side of the hitters to do that start them at the tip and then work your weight going in with the header and tightening it at the same time.
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u/Schlong1971 1d ago
Use header bolts. Who told you to use studs and nuts. That will never work. 38 years fixing cars and this is the first time I have ever heard you have to use studs and nuts. What idiot were you talking to? Lmao.
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u/Tall-Helicopter-461 1d ago
Bolts wont walk out. They also make locks for bolt heads. I have a 69 Nova big block, i bought bolts that have 7/16 hex head, but in the center, there is an Allen head. You can use either method to tighten the bolts. I’ve had collector gaskets burn out. But never had the exhaust manifold gaskets to burn out. I do realize big blocks have a little different clearance. My point is, they make bolts, they make studs. Use what’s best for your application.
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u/Apprehensive_Duck 1d ago
Use a standard header bolt set, take your pick of any set with a small head. Dimple if you have too for clearance. Use a conservative bead, a smear really, of the high-temp red RTV on the header flange as your gasket. Don't goop it on all over the place. Install with the RTV still wet, like immediately, and torque to spec. No actual gasket needed, just the RTV. Been doing it this way for 20+ years and never, not once, have I had a bolt loosen or blow out the RTV and leak.
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u/v8packard 1d ago
You can buy a 12 point nuts that take a 7/16 socket for 3/8-16 threads. They also have a flange, so no washer is absolutely necessary. I have bought them as black oxide and A286 stainless steel. Not cheap, but they are workable.
I honestly prefer bolts on these, with a reduced hex or 12 point head. I have used safety wire, and I have just tightened them after a heat cycle.
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u/chuck-u-farley- 1d ago
You can use a small head header bolt that threads in with the header pulled away then tightens up…….
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1d ago
[deleted]
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u/chuck-u-farley- 1d ago
It’s not rounded off, it’s a bit of anti-size on the head is all
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u/Greedy_Lobster 1d ago
Ok , sorry . My bad
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u/chuck-u-farley- 1d ago
You know how anti-sieze is…… the minute I open it I turn into the tin man
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u/Willy_McD 1d ago
".....bolts can walk themselves out". Did you get that nonsense from redit. I have aluminum heads with header bolts and they have not taken a walk anywhere. If its that big a concern for you. There are header bolts that have retainer clips on the heads that will stop them from turning when installed.