I'll have to agree with most of the posts here. A larger carb is not going to to help much accept with higher RPM. Low RPM may be lost, and that is where you need it for that truck. The original setup should perform reasonably well. I can't see spending the money on a new/bigger carb for your truck. You'll continue spending money for more gas if you do, and possibly have a power loss at low RPMs. Spend the money on a good tuneup and carb adjustment and/or carb overhaul. Remember that your truck is nearly 60 years old too.
