Theres a fair bit more room in the e36 and ive compared e36 m42 turbo manifold with e30 m42 turbo manifold and they definately are very different. the e30 m42 turbo manifold you cant really have 2 pipes going side by side if you know what i mean. it has to be one on top of the other or underneath.
I spoke to the chap that builds them and he specialises in m42/m44 turbo cars and he said it definately wouldnt fit. He had a m44 turbo for sale from an e36 compact but the manifolds would not fit my e30.