79 F100 coolant leak

[bowtruck]

First post here. I need some assistance with rejuvenating a 1979 F-100 V8 (351?) which has sat idle since 2005. I need to replace/repair what I will call the timing chain cover/water pump mounting unit. The piece developed a coolant leak. It is the version that has the dipstick passing through to the oil pan (and houses front seal). Nearby ford service manager suggested it would be hard to find a replacement part, but it might be that a machine shop could fix it instead. I'm without a manual but have removed pretty well all I can see that will keep it from coming free. Wondering if I need to drop/remove the oil pan, as the unit seems free at the top and the oil pan is all I can see that would still hold it in place.
Also, suggestions what to do before attempting to crank over the engine, ie, spray/squirt anything into spark plug holes to loosen pistons which may be seized? Is the old gasoline suspect? What else to consider? I live in a damp winter climate.
Thanks.

[bowtruck]

(correction, fuel pump not oil pump.)
Guess my post is not too interesting since no response has come. The unit has been removed. (was stuck at the oil pan seal.) Found a leak and I am carrying on. May soon turn into a small nightmare tho', as I race against imminent weather changes, and now find I will need to raise the engine to remove and service the oil pan, plus whatever else I happen upon. Think the timing chain may be too sloppy.
Oh well, life is a lesson and I have a good manual now.

[big white bufflo]

well you got the timeing cover of you should think about replaceing the timing chain and gear you can get away with losening the oil pan and when you put it back together use lots of silicone .also replace the seal around the harmonic balancer this is alot of preventive maintenace but well worth the money spent in the log run also put a little tran fluid down each cyl it will losen any ring that might have stuck from sitting then turn it over by hand drain all the old gas out of tank put fresh in replace the fuel filter and buy a spare because all the varnish will losen up and plug the filter you might have to rebuild the carb also good luck in your resurection