I am hoping you guys can tell me how hard and long it will take to do. It is a 1988 full size truck with a 3.9. I know the truck does not go here but more 3.9 here than in the full size thanks

 

It depends on your capabilities (and tools.) It isn't magical, you need a manual for torque specs, a set of sockets and maybe a pair of vicegrips, and a coupla torque wrenches (in./lb. and ft./lb.) Any halfway decent shade tree mechanic can do the job. Just pay attention, take your time, and be careful.

 

I have many tools but no torque tools. I changed a valve cover gasket on a 4 cyclinder nissan truck 2 yrs ago. I have done some minor work before and want to try other things.thanks

 

If you have a Harbor Freight near by, you can get a 1/4" drive inch/lb torque wrench for about $10. Same with a 3/8 & 1/2" drive ft/lb.

Mainly you would need the torque wrench to tighten the bolts on the intake manifold correctly.

This is not a difficult project. If you have any doubt that you'll be able to get things back together in proper order, take a bunch of pictures before you start.

Before you start to put things back together,you want to get the mating surfaces very clean and smooth. There are water passages between the heads and the intake manifold, I like to lightly seal the gaskets in these areas with copper RTV silicone.

Don't know about your engine, for the V8 magnum engines, Dorman makes a very nice complete gasket set. Mine was about $25 plus shipping from Rock Auto--the gasket set is very complete. Valve cover gaskets are extra--and for those I'd get Felpro neoprene.