[DeTomaso] Holley 650 problem

[boyd casey]

Hi guys. I am having a problem with my Pantera. I have a 73 L with a
Cleveland that has  some modifications. It has a Holly 650 (manual choke)
double pumper,
an Edelbrock performer manifold, MSD 6al box, blaster coil and an MSD 8577
Distributor. I don't know for a fact but I have been told that it has a mild
 upgraded cam , Hall big bore headers and mufflers. Over the past few days I
have noticed a deterioration in the way the engine has been steadily
deteriorating. At first I thought it just needed a tune up. I bought new
plugs but before I could install them the car stalled out around five miles
from home. When the engine died I started checking things out and I noticed
that the rear two barrels of the Holly 650 had allot of liquid gas sitting
in the bottom of the barrels. There was gas still pouring from what I think
are the secondary nozzles , and collecting in the bottom of the secondary
barrels. The car was not running  and in spite of the fact that I turned off
my fuel line ( I have an in line ball cock valve that I turned off when I
saw the gas pouring into the carb.) In spite of my turning off the fuel
supply the gas continued to drip steadily from the nozzles! ( I assume it
was gas that was already in the fuel bowl). I don't know allot about carbs
 but based on my limited knowledge I think it my be a stuck float. So I am
looking for advice.  Should I get a rebuild kit and rebuild it or should I
buy a new carb? If the recommendation is for a new carb should it be a
Holley or something else?  On a side note after I let the car sit for around
 1 1/2 hours (the engine cooled and a lot of the gas evaporated out of the
carb)  ( I also tapped the fuel bowl with a steel wrench handle in the hopes
that it might dislodge a stuck float )  Luckily I was able to start the car
and drive it home! So please share your advice.  It is my understanding that
Holley carbs require a change of jets to adjust the fuel flow. Are there any
carbs that can be adjusted with a screw instead of changing jets!
Thanks,
Boyd