318 Exhaust Manifold Bolts

I bought a set of used manifolds and I mistakenly thought that the "header" bolts I had would be long enough for the manifolds.

Since I have the thread pitch, can I just go to the hardware store and get some stainless steel bolts in the correct length?

I know you can buy a "manifold bolt set" but I am not doing a period correct resto, just want to get this 69 barracuda on the road.