Fuel Pump/Pressure

I have a 1986 S-10 Blazer 2wd with an LT1 350. I was getting 1 pound of fuel pressure at the carb until I pinched off the return line (in tank pump). Can I use a filter without a return line and just block off the return line to the tank? When I pinched off the return line, I had the 6 pounds of pressure I need.

There seems to be a few disparities in the description.

First, the '86 Blazer did not have a carburetor. Something is awry there.

Second, the LT1 (any of the three versions) was/is a V-8. Two of those versions did not have carburetors.

Next, presuming the '86 Blazer had an engine transplant, and presuming that engine uses a carburetor, it will be important to determine which carb is installed. Rochester 4MVs will operate just fine with one pound of pressure. Most Holley carbs , such as the 4150/4160, will operate just fine with one pound. Some Carters, however, need about 3 pounds to overcome the inlet needle/seat head loss to fill the bowls.

Can we get a bit more detail about the installation?

Normally a 1996 chevy would have a throttle body and not a carburetor
http://www.rockauto.com/ sells a rebuild kit for these units. They have a fuel pressure regulator built into them and the diagram goes bad,
I'm not aware of a S-10 having a 350 cu inch engine. I have worked on K-10 with a throttle body and a 350 cu in engine.