Two new leaks discovered

After changing my engine oil and radiator coolant, I discovered two new leaks. Not sure how long they've been there.

The first one is a slight radiator leak, dripping from the left radiator support. It appears to drip only while engine is running and not while shut off. Cannot tell where it's coming from, but it's not from upper left petcock that I had cracked open for ventilation while draining. Both hose clamps on lower radiator hose were lose, but tightening did not stop dripping. Questions:
How difficult is it to remove radiator for leak test and repair?
Are any stop leak products worth using?
What is radiator/engine (351W) cooling capacity?

Second leak is rear end. There is small oil spot on pavement underneath rear end. I have not put car on lift to closely inspect, but reaching under car, I can feel oil/grease on underside of tie plate.
Questions:
Do I have a bad seal in rear end?
How difficult will it be to dismantle rear end and replace seal?
Do I need a Jag rear end specialist to perform repair, or could a general Ford tech do so?
How easily can rear end grease/oil be added? What kind of grease?

Any ideas or suggestions would be greatly appreciated. Many thanks.
Walter

we have replaced one radiator already, leaking in seam where we couldn,t repair it.Not that tough to pull out for x-ray eye. Oil--ours drip some, just comes with it, I just wipe it up, and check diff. oil level from time to time. Did that last night. Wiped underside down, checked all fluids, inspected for loose bolts, looms, fanbelt, finally got tired and went to bed about ten -thirty or so.Even rolled tires and wiped rims on inside. Good luck--see you in gadsden? Will-alabama

More than likely it's a stub axle seal leaking. If so there is info on the forum about the repair which can be done without removing the differential. These o - ring seals cannot be replaced (no replacements, many different sizes). What you do is basically clean everything up and use RTV sealant with the existing o rings to stop the leak, works fine.
There is a right and left stub axle, you will have to determine which one is leaking.
You have to pull the axle and brake calipher on the leaking side.

Thanks Will and Rick. I'd like to try checking and adding differential fluid first. Never checked it before but will figure out how to do so. How difficult is it to check level? What kind of oil/fluid should I use? Unfortunately, I won't make it to Gadsen this weekend. My son is coming to town for his Birthday.
Walter