What is the correct size for head bolts for a 6-bolt engine? 10mm, 12mm? 13mm?

[tux2122]

Im doing a head gasket replace on my 6 bolt and I am trying to shop for new head bolts to put into the car. My Haynes manual says the head bolts are 13mm but I had to use a 10mm hex socket to actually get the bolts off. When I go searching around parts stores and places I get vastly different answers on what my head bolts are and what I need. So my real question is what size are my head bolts actually? Are they actually 13mm, or are they 10mm or another size?

Also just a thought, the person who I bought the car from did the 6 bolt swap, could he have used a 2g head and thats what I need to use? Whatever comes on the 2g?

 

[ddavisaf]

No, the bolts you have are not 2G head bolts. 1G's use the hex 2G's use an inverted torx.

 

[ddavisaf]

Chilton's says 13mm, we pulled 10 mm. Dealership says 12mm.
So now I'm curious.
Post your findings everyone. What size headbolts did you pull out when you did your headgasket swap?

 

[sleeper04]

The 6 bolt block is 12mm. If you are using a 2g head You must drill the holes to 12mm in order to fit, but if your using a 1g head they are 12mm.

ARP