Previous owner applied undercoating to the underside of the hood. This makes the hood heavy and will it stay fully open. Does the undercoating actually help with sound deadening inside the car?

My '53 was done the same way. It must have 20lbs of undercoat on the under side of the hood and it won't stay fully open. I added some booster springs but only got maybe two more inches of height on the hood. If I could figure a way to remove it without damaging the hood I would. A chemical stripper of some kind would make a huge mess and heat could warp the hood. I have no clue as to what perceived advantage there was to putting it on the hood.

My 52 was undercoated under the hood. It stayed open until I put a drop of oil on the bolts.

The dealers often undercoted the hood when car was new and owner paid for the undercoating. They thought they were doing you a favor by making a heavy coating. Yes, it will deaden some engine noise and prevent the engine heat fron damaging the paint. Difficult and messy to remove.

There is also a discussion of this topic over on ChevyTalk

I stripped the undercoating off the Firewall of my 34 Master with a putty knife. May work on your Hood, may not. Lot less messy.

With the hood off a lot should be able to be removed with heat from a heat gun and scraping then wiping down with a solvent. Doing small sections at a time should prevent any distortion from happening.

That's my discussion on Chevy talk. Trying to cover all the bases. Great knowledge base on both forums.

Diesel fuel will soften it up, but is rather messy to work with but it works pretty good