Factory crossover bolt thread size

[gm5150]

I need to tap the header flange where the crossover mounts to the header.
Can someone confirm the thread size, is it m10 X 1.5 X 40?
If so, would this tap work?
https://www.ebay.com/itm/1-Greenfie...693193&hash=item3b058e8424:g:QaQAAOSwZVJarEND

Thanks,
GM5150

 

[gm5150]

Anyone?
Nobody has ever tapped the threads on the header to crossover flange?


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[pacecarta]

just so im up to speed here ... you're asking if a M10x 1.5 tap should be used to tap threads where a m10x 1.5 bolt was ..really??

 

[gm5150]

I'm just trying to determine the correct thread size.

 

[pacecarta]

...m10 x1.5 is what the bolts were from factory so.... wouldnt you think thats the thread size

heres a parts diagram .. http://gnttype.org/numbers/partsdiagram.html
the bolts for crossover are shown as part # 57....

 

[gm5150]

Yup, I was just making sure is all.
Thanks


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[earlbrown]

Yes, the X-over bolts are 10mm metric. I have to make sure to label them and bag them separately in my ex manifold bolt kits. To the naked eye they look just like the SAE fasteners that hold the headers to the head.

 

[Gary Durden]

Almost every hardware store has a bolt size checker.