What would be your best guess to this? 1979 400m, 89,000 miles ,one owner farm truck, no smoke runs smooth, gets oil changed regularly. Starts running a little rough day by day, gets worse and worse,new plugs added...no difference. Still starts up but misses ....carb cleaned (spray)...no vacum leak noise detected

 

You didn't say anything about whether the cap, wires or rotor were ever replaced.
What about the fuel filter? Some things escape us when we are so busy.
Since you depend on it , keeping it running well is quite important and winter is coming.
If the routine maintenance is being done, there are some other considerations, but lets see where we stand for now, maintenance wise.

 

Thanks...guess i was looking for a little brain push...I know that my post could have a hundred reasons for an engine to run poorly..by the way this is a truck sitting in Illinois, 400 miles away and I am buying it over the phone ..things I mentioned were related to me from seller, and was condition of motor when she parked it behind barn 4 years ago , lol. she did a couple things Like new plugs and friend told her the carb ,being original , probably needs rebuilt . I am actually going to go out there and see if I can get it in condition to drive home and am making a list ...so anything any one can tell me will be appretiated...should be fun...stand by for more news of the excursion...

 

Since its been parked behind the barn for 4 years I would consider taking some of the following.
Fresh Gas (5 Gals)
dri-gas
20 feet of tow chain
portable air compressor unless they have air available
bug and hornet spray
old tire to place between vehicles if you have to tow it off the road
can of penetrating oil
If its an auto trans (the correct trans fluid)
Anti freeze
I'm sure you can add to this , but it was fun making the list.
Don't forget wiper blades

 

Thank you hanky...she pulled the truck with her tractor to the middle of side yard to sell and take photo's for ebay...so the bee's are gone..she did say that rear wheel drum was locked up...I learned that soapy water was good for freeing up brake shoes etc. she also poured a little gas into carb and it starts.

 

Boy !!! Some guys are just lucky.
( I would still not leave home without the tow chain)
You could always , as extra insurance , take her back on the trip home with you !
Just kidding!