cudajim
cudajim
I have a stock 225 6 cylinder exhaust on my 67 fish. I'm wondering if I should use hardened bolts for the exhaust flange or go with non-hardened ones.
For exhaust use hardened. Minimum grade five, preferred grade 8.
I can see using G8's exclusively so that you know that's all that ever can get used. Eliminates accidental use of a lower grade where its important that a G8 be used. But if a guy is going to have to buy them specifically for this application and isn't buying more for stock I don't see the need for the extra strength and expense. Fine if you want to do it, but not necessary.
I've had to replace just enough exhaust manifold studs because of galling to exclusively use brass nuts there too. When I first used them I was paranoid about them not doing the job. That's not a worry anymore and hasn't been for more than a decade.