Overpipe to Header Bolts/Nuts
 

Anyone know what size and grade bolt/nuts should I get for the connection of header to the overpipe? I just bought a used header and a used over pipe and neither have bolts/nuts.

Not knowing the brand of header or over pipe, I'd suggest take them up to a hardware store and buy the largest ones that will go into the holes and you are still able to fit the lock washers over the bolts and get a wrench on them.

Back-in-the-day we would just rummage around in the wooden boxes underneath the workshop bench till we found a couple that came close.

HINT: If you found one that is perfect, don't waste your time looking for a matching one ...... it ain't there.


humfrz

Grade 8, M10 x 1.25 x 40mm bolts, and flange nuts (the ones with a wide base)

Use the OEM MLS gaskets with the crush ring. The graphite ones are useless.

Use factory torque as a starting point, but remember you're using different materials, and the torque settings are no longer good. you may need to increase the torque significantly.