Ford Repair: engine timing, engine cranks, auto parts stores

Question
QUESTION: I have a 79 ford 4-wheel drive i'm restoring with 351 modified engine, cranks and runs perfect untill you try and drive off then engine starts loading up and chokes itself out, should I advance timing and how much if so ?

ANSWER: Need a little more information.Did the truck come with an automatic or manual transmission?What series is it(F-100,150,250,etc.)?

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QUESTION: It's a F-150 with automatic trans.

Answer
Is your ignition timing is set where it is supposed to be?(6 degrees TDC)Advancing your timing 4 degrees to get your timing at most 10 degrees TDC might help, but it sounds like your timing chain needs replaced.Most Auto Parts Stores will stock this item, plus it would be a great time to change the water pump,if needed, and several seals and gaskets.