I hate to have to make a post like this, but I purchased a set of Hi-Tek manifolds for my 18 with a 351W. The parts came from China and look very nice cosmetically, but the bolt holes do not line up with my engine (and the exhaust gasket supplied with the manifold) at all. At the end bolts they are out at least 1/16". Some of the holes are so close the the exhaust channels that I can't grind them out to fit without grinding into the exhaust channel.
This is the second set that came from them - the first time they sent me the wrong parts by mistake. Alan appears to be a stand-up guy and exchanged the first set of parts no problem, but this quality issue is a good reason to be very wary of these parts. Unfortunately, because the manifold and riser design is a good one in theory.
Just wanted to let everyone know of this situation in case one of you is considering ordering a pair.

Hope those of you in Florida were not hit too hard.

- Don