How stiff should mechanical Type 4 Fuel Pump be?

You can buy an SSP new mechanical replacement. Wouldnt bother messing with electric pumps and Malpassi pressure regulators which work out more expensive.
Or get a Carter internally regulated electric pump, also more expensive.

 

I think all the currently available mechanical pumps are from the same source in Slovenia. I have one on but it required some modifications. I still travel with my old one as a spare, though it does weep a tiny bit from the top plate (the fuel cut off valve cover). They warp it seems.

 

Another one to close off. I made some gaskets, cleaned up and packed my spare pump with grease. So far, so good.