Main and Head Bolts


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By Rono - 14 Years Ago
 I am looking to replace both the stock Main and Head bolts with new Grade 8 bolts (don't want to use studs) on my C2AE block build. When I measure the length of the 1/2" main bolts, they are 2.900" long. Can I use new 3.000" long bolts without redrilling?

Also, the shorter 2" head bolts actually measure 2.125 but I assume this may be due to stretch over the years, so I plan on using new 2.000 long bolts and call it good. The longest head bolts I measured at 4.300". I can't find any 4.250" long head bolts, would 4.500" long bolts be okay without redrilling? I heard that the C2AE blocks were drilled deeper so I think I will be okay with this plan.Unsure

Thanks,

Rono

By Hoosier Hurricane - 14 Years Ago
Rono:

The 3" main bolts will be OK, but check that the rear cap is not shorter than the other 4 to clear the seal retainer.  If the cap is shorter, the 3" bolt will probably be too long.  For the head bolts, I would screw the 4.5 bolts in the block by hand and measure them to be sure they are not too long.  I'm guessing they will be too long. 

By charliemccraney - 14 Years Ago
www.mcmaster.com



Gr8 7/16-14, 4 1/4", 91257A686   $8.67/pack of 5
By marvh - 14 Years Ago
Personally I would use ARP bolts instead of grade 8 bolts. If you check the ARP site you will be very surprised at the substantial difference in tensile strength between the ARP bolts and grade 8 bolts.
http://arp-bolts.com/  
Mummert sells them in packages for 292 or 312 engines. I have seen too many head gaskets blown  especially diesel engines from a lack of quality head bolts.

marv
By The Master Cylinder - 14 Years Ago
charliemccraney (11/17/2011)
www.mcmaster.com



Gr8 7/16-14, 4 1/4", 91257A686   $8.67/pack of 5




Awesome link Charlie. I see they have a warehouse in Santa Fe Spring, CA ~20 mi East of me.



Thanks
By Rono - 14 Years Ago
Guys;

Thanks for the advice and info...I'll reconsider things.

Rono

By LordMrFord - 14 Years Ago
Hoosier Hurricane (11/17/2011)
Rono:



The 3" main bolts will be OK, but check that the rear cap is not shorter than the other 4 to clear the seal retainer. If the cap is shorter, the 3" bolt will probably be too long. For the head bolts, I would screw the 4.5 bolts in the block by hand and measure them to be sure they are not too long. I'm guessing they will be too long.




2 x ARP 653-2250

2 x ARP 653-4500



Those three upper center bolts are a little bit (~2mm) too long, but I got 1,3mm chopped heads.
By ecode ragtop - 14 Years Ago
Rono, If you are going to bolt on a supercharger, don't take any short cuts on bolts! I used a.r.p. in my lincoln y-block and i am only running 6# of boost.
By Rono - 14 Years Ago
You guys have convinced me...I'll go with ARP main and head bolts.

Rono

By charliemccraney - 14 Years Ago
Correct me if I'm wrong, but I do believe that the Hoosier Hurricane uses Grade 8 bolts. They are 1/2", though. See them just behind the head?







ARP is great, but for the budget minded, I think grade 8 will do the trick.
By Hoosier Hurricane - 14 Years Ago
Charlie:

You're right, the bolts in the pic are 1/2".  But I blew two head gaskets at Columbus that weekend.  I now run 1/2" ARP studs, so far they are holding, but I have backed the boost off a tad.  Also added a post at the spot that kept blowing.