My 87 sami has a rebuilt 1.3 with flat top pistons shaved head isky torquer cam pacesetter header and a weber 32/36 the truck runs great around town but offroad when on an incline the truck stalls  out. When it does this I have to pin the throttle to the floor to get it to start back on the hill like it is flooded. The Sam will climb anything in lowrange I'm assuming because my rpm's are staying high while its in low lock. I did install an electric fuel pump and the gauge I put inline stays in the 3.5 to 4 pound range. I'm new to the forums  so sorry if I rambled  but any help or suggestions would be greatly appreciated thanks.

is the float bowl to the firewall or toward the radiator?
if it is forward, then you might be overflowing fuel. this may be reduced by lowering the float.
turning the carb around(bowl to firewall) works better.
easier to deal w/a little flooding going downhill, and with some float adjustment mabe not notice it much.
also mabe try 3lb or less fuel pressure(2lb works for me)