Classic/Antique Car Repair: 1967 Ford Galaxie running terribly rough., ford galaxie 500, chevy guy

Question
Are the rocker arms something I can check and adjust myself or is that something I could really screw up? Thanks for your help!
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Followup To

Question -
I'm completely new to cars, having never changed my own oil, but I just bought myself a 1967 Ford Galaxie 500 and I'm starting to try and learn. The books I have so far are very helpfull, and I think I could do a lot of things just with the boks and some tinkering, but right now the car has me stymied.

When I bought it 4 days ago it ran fine for an hour, sat in the sun running with no overheating problems, and seemed to run great. We drove it on the highway for 20 minutes with no problems. Now it just barely starts, runs terribly rough, and stalls if I take my foot off the gas.

The guy who sold it to me said he took a little pressure off the rocker arms when he stored it for the winter and hadn't torgued them back down yet. It's maybe been run all of 5 minutes since I got it home and I'm very frustrated by the whole thing happening before I even had a chance to learn about it.

I also noticed that a pan under the car, behind the engine, which I think is covering part of the transmission, is covered in oil and it has leaked some oil, but the oil still reads full and is clean.

The engine is a 390 (the original engine from 67' I think) and it has a newer Holley 4 barrel carb. The guy who owned it seemed to know about cars, but is not a mechanic.

Could it be the rocker arms? If so how do I get it to the mechanic or can I fix it myself? Maybe all that oil on the pan under the car (I don't think it's the oil pan because it's farther back but I could be wrong) is part of the problem?

I know you're a Chevy guy, but your my best hope at the moment. I just found the site and I think it's great, I'm going to volunteer in an area of expertise of my own right now. Thanks so much for your help.

Answer -
Chris :
 Hi - well it might just be a carb. adj. or the choke might need a adj.  and when was the last tune up. I do not think it is the valves causing it. and the oil , well thats the tranny convertor cover and it could be the seal or a oil leak ,tranny leak , you would have to get under to see where its comming from. most all fords leak something .any ways

Answer
Chris ;
  Hi well the rockers are not that hard to check but if you set them wrong , they could cause a lot of trouble,  I would go to the library and go to the auto section and look in the tech. books for fords - you will find a section all about the valves and the adj. of them. and for your car.  ok
it is not a big - deal all you do is remove the valve covers - w/o breaking the gaskets and than check the setting on the valves when running ,   you will have oil shoot all over so you should get some oil clips that go on rocker arms  
to cover the   push rod hole where the oil shoots out of , it can be a bit messy.and with a feeler gauge with the proper setting you will loosen the rocker nut and set the tappet and valve clearance . and if you have hydraulic valves than its easy , you will loosen the nut till it clacks than tighten it till it stops than 1/2 - 3/4 turn more . too tight can burn the valve out - if the book tells you the setting for hyd. do what the book tells you to set them at. it is not hard.