Rear coolant manifold question - OK to remove and block off?

[shaymus]

I'm putting a M60B40 engine from an E34 into an E30. I don't intend to run a heater core, and the water manifold is hitting the firewall. I've though about cutting into the firewall to make more clearance, as well as cutting off the hose flanges and welding them shut. I think the easy answer would be to just remove the manifold altogether and block off the openings with a plate on each side. That would leave the return pipes going back to the water pump to deal with, and I'm thinking to plug up the water pump where these return pipes go.

Does anyone know if blocking off the rear manifold would be detrimental to anything? There are 2 water temperature sensors on the manifold, and I assume they are related to the climate control - again, I don't need that. But, what are those 2 sensors for?

Any thoughts or recommendations would be very much appreciated.

[ross1]

Don't eliminate the water crossover, it is essential. One sensor is for the DME

[moroza]

Pretty sure the big pipe leading to the waterpump from that manifold is either the main Send to or Return from the cylinder heads. It's essential for flow through the heads.

[shaymus]

Thanks for the replies. I'll look into making more space for the manifold and blocking off only the heater core pipes.