I believe user mramay is in progress of stuffing a LS2 in a 126 currently, but it's being slow.

From what I was seeing on the 126, you end up with the steering interfering with the oil pan and block, as well as having very tight routing for the exhaust. It also required some creative modification of the cross member to allow space for an oil pan.

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-Josh
Testing the cheap Mercedes axiom, one bolt at a time...