blasgg, theJPster's post was almost four years ago. Time has moved on and if you search for "exhaust manifolds" in this site you would find updates of the latest discussions - the gist is that factory originals are no longer available even though you have the moeny; buddies are trying other solutions; the most feasible being fabricating factory originals with the minimal of modifications to be practical - ensure tight fit and fit-all applicability (across a range of many options - with or without air injection, with or without exhaust gas recirculation 'EGR'), and minimize costs. We have yet to hear from all those who have indicated determination to overcome this enduring problem.

 

I still think the likely easiest solution would be to have someone take the OEM manifolds and build a simple pair of stainless "logs" with the ports for EGR and air injection welded in, and plugged if you don't need them.

XJREngineer sells the plans to cut the manifold faces.

That would be a lot easier than trying to build full equal length headers, and the performance would probably be fine.

A lot of the GM 3.8 builders actually prefer the "log" solution.

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Agreed with Al. Just hope someone will make this happen, and benefit all so we need not worry about this anymore when old ones crack or welded ones crack again.