I like to keep my whole engine compartment clean and shiny and here's what I use:
Engine degreaser - any brand will do. Autozone and Wal-mart both have their own for $1.00 or less. One can is probably enough.
CD7 (or something like that) Engine Detailer. This is available at WalMart, among other places that creates a protective coating over everything in the engine compartment.
This technique makes the engine compartment look like a new truck and it lasts a long time and makes keeping it clean easier.
Find a place where you can make a big mess on the ground.
Take off your air cleaner and cover up the input to the carb so that no junk can get sprayed in it.
Spray the degreaser all over in the engine compartment, even on the firewall and wheel wells.
Let it sit according to product instructions
Get a hose with low pressure and hose all of that crud out of the engine. Avoid getting water in the distributor, carb or breather (or anything else that logically shouldn't have water in it. It is fine to get the block/heads wet. Stuff that looks like dirty milk will run everywhere.
Allow to dry (read the can)
With the carb still covered, spray the engine detailer all over your engine, fan shroud, hoses, firewall, wheelwells, etc. Don't spray it on your belts, in the alternator or in the carb.
Once it's done dripping, just run the truck to get the stuff hot so that it cures.
Now everything is very clean looking and shiny (not high gloss, but a neat, even satin). It will also be easier to keep the engine clean now.
The detailer is not harmful and can be cleaned off with more degreaser or some elbow grease. It is MUCH better than trying to use Armor all under the hood, since Armor All will be washed off in the first rain.
'85 JIMMY
'90 paint/grill/trim 5"susp 33/12.5/16.5
Fresh 350 B&M '87 TH700