Don't forget to support the manifold with a brace down to the block, or you get cracking around (through) the bottom of the front inlet runner. This happened to both manifolds I had, I sold the first one broken, then had the second one repaired. There is a factory brace there, but ignorance on my part meant it was left off. The manifold itself is top heavy, so it rotates around the studs, & obviously cracks. Making a support wouldn't be too hard, just some round hollow steel tube. Measure the length needed, add a bit both ends, then flatten the end in a vice & drill some holes to bolt it through. I had the cracked section fall right out, causing a massive vacuum leak.