sounds like you may have a hole in the Diaphram of your fuel pump. If that is the case, check if the vendor will repair or replace. (still have receipt?).
-I'd pull the oil pan get it thoroughly cleaned and inspect everything when your down thar.
-change gasket, blah,blah,blah
-straighten your oil pan.
-reassemble and oil it back up .
-remove faulty fuel pump and repplace with known good one or,
get a 24 V electric fuel pump like the ones used for the Southwind Vehicle heaters (facet or Carter) you should be able to run either without the need for a fuel press reg.
-clean out air filter and change oil in..
-check carb float level clearance at 9/64" (not 1/4")
put back together..
-clean all plugs
-check compression dry (might as well understand the wear of your cyl /valves now)
crank her to start
the f134 requires no pumping of the throttle to prime carb (that is if all is to spec)
method is pull choke about 1/2 out of its cable travel and set throttle cable 1/8th out for holding rev idle once motor starts.
adj throttle to 1200 rpm by ear.
let rev till temp at 135-140
push throttle cable back for rpm at 600 and temp till 160-180
vacuum test....
good link
How to Use and Interpret a Vacuum Gauge
observe needle behavior.
set air /fuel on YS carb. close the mix screw in and back out 1/4 turn till you reach best vac smooth idle. take screw back in slightly for leanest margin.
check timing. (have you a timing mark on your Pulley and pointer designating TDC and 5 deg AdV?
test drive.
remember... we are still trying to find out if indeed you need to pull the motor for a rebuild