How long are Gen 4 head bolts?

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Jun 25, 2010 | 05:35 PM

Hotrod406

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From: Hamilton, MI

How long are Gen 4 head bolts?

Can someone measure a set for me? I need to know the under-head length to see if they will work in my application (not LS1). Thanks!

Jun 26, 2010 | 09:22 PM

Hotrod406

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From: Hamilton, MI

54 views and no one has a bolt he can measure? I thought this would be a slam dunk. Somebody's got to have something.

Jun 26, 2010 | 11:08 PM

hotswap

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I just happen to have a brand new set of OEM head bolts for an LS2 and i just walked out to the garage and measured them. The long center and lower bolts are 4 5/16'' or about 110mm and the smaller upper bolts are 2 1/16 or about 52mm. These measurements are from tip to tip. I hope this helps.

Jun 26, 2010 | 11:26 PM

Hotrod406

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From: Hamilton, MI

Thank you very much. That rules out Gen 4 bolts for the Northstar that I need to fix. Several of the head bolt threads pulled out of the block and I wondered if I could use 1/2" head bolts for a Gen 4 (the next size bigger than the stock 11x1.5 Northstar bolts) instead. It doesn't look like that's going to work.

Does anyone know of a motor that has 20 5.5" long 1/2" head bolts? I thought Ford Cleveland but those are only 4.5" long.

I'd rather use 1/2" bolts or studs than the inserts.

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