350 head bolts?

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Steve-o81

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I was wondering if ARP head bolts will make a difference that much. I’m doing a build of an engine I had when I was younger. A 50K original mile 350 medium duty P-Series engine I had. I put Hedman Elite headers on it and the head bolts all came loose in like 1000 miles. If ARP won’t help that much I’ll stick with the factory cast iron exhaust manifolds. Will ARP head bolts significantly help to illimitable them from coming loose?
 

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Head bolts or exhaust manifold bolts? If you had a problem with something coming loose, you didnt properly torque it. Using ARP instead of stock isn't going to help you at all with that. The purpose of using ARP bolts is that they are stronger, but that also means you need to follow those bolts direction for torque specs or they will come loose as well.
 

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Head bolts aren't going to keep headers from coming loose. I also don't think the headers caused the head bolts to loosen.

ARP head bolts are very much so worth the cost and I personally would recommend them on any engine, just for the reassurance, over old head bolts. As for headers coming loose I've had good results from these bolts

https://www.summitracing.com/parts/pro-66753

And these gaskets

https://www.summitracing.com/parts/rfl-2006

Like others have said torque rating, sequence and order is massively important with any bolt.
 

Octane

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Header bolts arent head bolts
 

Steve-o81

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Header bolts arent head bolts
I know for some reason my head bolts came loose with the headers for some reason. I had no issues for some odd reason with the exhaust manifolds until I put on headers. The dang head bolts not header bolts came loose. So I think I should stick with exhaust manifolds. Thanks!
 

Octane

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I know for some reason my head bolts came loose with the headers for some reason. I had no issues for some odd reason with the exhaust manifolds until I put on headers. The dang head bolts not header bolts came loose. So I think I should stick with exhaust manifolds. Thanks!
Simply no way properly installed/ torqued head bolts can loosen tho,by installing headers and its fasteners. There are header bolts made with a clip to prevent the bolts from loosening and causing exhaust leaks.Cant remember the name of them tho.
 

Steve-o81

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Simply no way properly installed/ torqued head bolts can loosen tho,by installing headers and its fasteners. There are header bolts made with a clip to prevent the bolts from loosening and causing exhaust leaks.Cant remember the name of them tho.
I had my relative who owns his own mechanic repair business do the job. Maybe the mechanic forgot to tighten up the head bolts. He had a lot of trouble installing the headers to fit on the 350 in my originally a 305 engine bay 1981 Silverado. It was a tight fit for him. Thanks, I suppose it was his fault I’ll try the headers again then.
 

Bextreme04

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I had my relative who owns his own mechanic repair business do the job. Maybe the mechanic forgot to tighten up the head bolts. He had a lot of trouble installing the headers to fit on the 350 in my originally a 305 engine bay 1981 Silverado. It was a tight fit for him. Thanks, I suppose it was his fault I’ll try the headers again then.
This whole thing makes my brain hurt. What did you have done? A 350 and a 305 are identical dimensions externally. If you had the heads worked on or removed, why would you think that headers would have caused the head bolts to back out? There is zero possibility that the headers rather than manifolds caused head bolts to back out.
 

Steve-o81

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This whole thing makes my brain hurt. What did you have done? A 350 and a 305 are identical dimensions externally. If you had the heads worked on or removed, why would you think that headers would have caused the head bolts to back out? There is zero possibility that the headers rather than manifolds caused head bolts to back out.
The shop that installed my headers said they were a pain and very tight fit, I looked underneath and they were almost hitting the underside of the truck they were so tight. I assume that’s where he had trouble and possibly loosened the head to help himself out. I put 10k on the truck 9k with exhaust manifolds and 1k miles with the headers after the headers put on they loosened quick. Thanks I’ll try the headers again. Heads were stock P30 step van heads same as the entire 350 engine they were on.
 

Steve-o81

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The shop that installed my headers said they were a pain and very tight fit, I looked underneath and they were almost hitting the underside of the truck they were so tight. I assume that’s where he had trouble and possibly loosened the head to help himself out. I put 10k on the truck 9k with exhaust manifolds and 1k miles with the headers after the headers put on they loosened quick. Thanks I’ll try the headers again. Heads were stock P30 step van heads same as the entire 350 engine they were on.
Also the engine was installed correct and level but it sat up so high if I used a 3” tall or higher air filter in my open element style air cleaner the hood wouldn’t close. That’s how tight this P30 350 from the 70s was under my hood on the top side alone.
 

Steve-o81

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Also the engine was installed correct and level but it sat up so high if I used a 3” tall or higher air filter in my open element style air cleaner the hood wouldn’t close. That’s how tight this P30 350 from the 70s was under my hood on the top side alone.
Also it had an Edelbrock Performer intake and Edelbrock 600cfm carb
 

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