E30 Zone

I'm starting a conversion with a M52tub28 engine from an early E46 into an E30. I've bought an E34 sump conversion kit but when the oil pump is fitted the chain is far too loose. The original oil pump is all part of the alloy plate which runs the length of the sump. Does anyone know of a sump change suitable or a front crossmember conversion? thanks James

Sump is Ok. Just get oil pump from e38 728i (there was 2 types so check before you buy one)
Pump from E46 might be ok but need just part No.2 from e38