Bolt Question (see pics for reference)

[M.Cueva]

I have tried and tried to figure out what type of bolt would go in the block (see pics below). I have remove a waterpump bolt and tried to manually thread it in one of these holes, have gone through every extra bolt in the drawer (and I have a LOT of them) trying to figure out what the heck fits. I have even tried to consult the GM service manual and diagrams....no help there.


I am trying to complete my engine block to ground wire and I dont feel like pulling the bolt under the exhaust manifold when these pretapped holes are right there. Thanks guys for any help/light that you might be able to shed on what I might need.

 

[Zembonez]

Looks like metric 8mm tap to me.

 

[M.Cueva]

hmmm, dont think I have any of those bolts. Time to go mobile (down to the local grange store).....

 

[Black02Silverado]

Do you have a tap and die set to go through to see what fits?

 

[Zembonez]

Hit Advance auto parts up. They have a pretty good selection and you can go out and make sure it fits!

 

[Bigredmariner]

All 3 of those are 10mm bolt holes.

 

[M.Cueva]

Just got back from Advance Auto. Guy behind the counter looked at it and told me that they should have been 10mm bolts. Tried them and no go, so he got a handful of product and tested each one. Turns out that the correct size is 3/8"-16 (Advance Auto part# 960-215 - http://shop.advanceautoparts.com/we...LUE4&srccode=cii_10043468&cpncode=30-952005-2). Got me some grade 8 bolts (.02 more than grade 5) and now I have finished this part of my wiring...I really need to get a tap and die set though.

 

[Bigredmariner]

Very strange, I have the same cast# of heads on my 06 and I screwed a 10mm into all 3 holes. At least you got the right ones for yours.

Sent from my super slick HTC Thunderbolt.

 

[M.Cueva]

i wonder if my heads are "defective" with the OEM tappings....(not that I really care)

 

[Bigredmariner]

Hard to say, it won't hurt anything at all. It's just strange that they're different.

Sent from my super slick HTC Thunderbolt.