19 Nov 2024:
I know this is out of order, but wanted to keep the body work together as a section. While the car was away, work did not stop. A six-month long process between myself and Rob from @NeedsWings commenced. The desire was for well made stainless steel exhaust manifolds for the M156. Unlike M113/M113K conversions, there is no easy way to arrive at a Crossfire compatible exhaust manifold. The whole thing would have to be fabricated. Rob did not have a M156 around, but at this point, there were 5 in my shop (I have a disease, I know). A M156 head was shipped up to Rob, and he began designing a flange. Locally, a spare M113K with Crossfire manifolds was put on a stand, and jigs were built that would locate the proper spot and exhaust outlet should be for the stock Crossfire downpipe. The jigs would then be bolted to an M156 which has the same bellhousing pattern as the M112/M113. This would help locate the new manifold's outlet. Rob sent several prototypes in more or less skeleton construction, and I would make slight adjustments. Many back and forth shipments happened until we got to the final form.

This is a stock M156 exhaust manifold on the engine. Notice that the manifold points more or less straight down, and it is sticking way off the side of the engine. Both a no go for the Crossfire.


Here's the first successful hack at the new manifold. Yes it is incomplete, and yes it is messy. The good looking welds are Rob's and the horrible looking ones are most definitely mine! You can see the jig bolted to the end of the manifold.


Here's a shot showing the flange bolted to the jig. This is how we located the outlet of the manifold.



View of the left side manifold mock-up bolted to the jig from above. You can see the difference of placement of that outlet from the stock manifold.


Final manifolds, with ceramic coating applied

Final manifolds, with ceramic coating applied