it's been 10 years or better since i've had to work on an engine that wasnt fuel injected. i just baught a 1980 e150 van and was told it just needed new plugs and wires....basic tuneup. NOT the case. upon looking around i discovered the tuneup has been done. so heres the deal, i haven't timed a car in a while, but when i put the gun to it the mark was about 3 inches away from TDC. set the mark to it and the rotor lined up with the #1 wire on the cap. i want to think it's timing is retarded but i cant remember how to change that. laugh now if youd like. sprayed some carb cleaner around the carb and intake manifold and discovered a leak at the #6 intake, could that cause it to run shotty? i guess i could mention that on the road it runs ok, but likes to have full throttle or no throttle. the motor is the 300 1bbl carb straight 6. i hear it's a good engine when tuned properly. also there is a spot on the nose end of the carb that looks like a hose is missing. dont know what it is for. thank you to anyone that can help.

 

....yep the 300 six is a tough motor.Had an '81 which I put in my '69 F100.The 'log' manifold bolts and studs can work loose,at which point you'll need to replace the manifold gasket.Ifso,you may also want to relace all bolts and studs with new grade 8 ..I believe they're 3/8"x2 1/4" bolts...studs are 4" I THINK.Are you missing the vacuum advance hose(s)to the VA unit on the distributor?I believe there should be two hoses....one each to the dual diaphragm VA unit.If you have only one on the VA unit somethings been 'monkeyed'.
Threre is also a vacumm hose to the air cleaner horn controlled by a temp/vacuum switch.I'd get a Chilton/Haynes manual to refer to....

 

i was hoping to avoid buying a manual, but i kinda figured id have to eventually. thanks for all the help though.