So I have a 95 Chevy with the 4.3 TBI engine. The OEM in tank pump should be regulated to 10-13psi. I want to install a GM 6.2 Diesel. Has anyone tried keeping the in-tank gasoline pump with an aftermarket fuel pressure regulator? What is the supply pressure requirements (upper and lower limits) for the 6.2?

The pressure regulator is in the throttle body, not in the pump. So you will need to add a regulator to use it.

yep in the TB, but it should work fine. We use the rear tank fuel pumps to push diesel to the front tank (2500 SUV's have dual tanks) and we never have any problems with them.

What's the maximum/minimum pressure requirements?