What size head bolts

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Sep 28, 2006 | 10:21 PM

jl2152

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Joined: Oct 2002

Posts: 49

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From: Spanaway WA

Car: 88 IROC-Z28

Engine: 5.7 L TPI

Transmission: TH700-R4

What size head bolts

I have a stock 88 IROC with a 5.7 where can i look to find out if it the head bolt size and whether or not its a 2 or 4 bolt main.

Sep 28, 2006 | 10:38 PM

Apeiron

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From: Mercedes Norte, Heredia, Costa Rica

Car: 1984 Z28 Hardtop

Engine: 383 Carb

Transmission: 4L60

Axle/Gears: 3.54 Dana 44

SBCs all use the same size head bolts. The threads are something like 3/8-16 IIRC, and there are 3 different lengths used. To tell if it's 2 or 4 bolt main, pull the oil pan off and look. If it's stock, chances are that it's 2 bolt, not that it matters.

Sep 28, 2006 | 11:25 PM

Sonix

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From: Calgary, AB, Canada

Car: 1982 Trans-Am

Engine: 355 w/ ported 416s

Transmission: T10, hurst shifter

Axle/Gears: 10 bolt, true-trac, 3.73

I think the head bolts are 7/16"-14 actually.
you definately don't want to pick up bolts from the hardware store, if that's what you're thinking. You need like the grade L9 or better. I think a head bolt kit from mrgasket, or better yet, ARP, would be best.

I wouldn't lose sleep over the 2/4 bolt, that's an old hot rodders fantasy tale.