In the 1940s, I believe the car hoods were shaped in a way that they came down around the top of the engine. It wasn’t the seal around the hood that created the bubble, it was the shape of the hood. Today’s car hoods are flatter; much flatter.
Regardless of what you have said Oldbodyman, I drive an 82 Suburban, and I have NEVER seen it form a pocket of air under the hood. EVER! I recently drove it (VERY SLOWLY to keep water out of the intake for the old 6.2 Diesel) and I can assure you it did NOT create a pocket of air. I kept moving completely through the flooded road I forged, then stopped immediately after… The engine had water on it, and so did the fender flares… so did the floorboards of the truck. There’s no way you can tell us that will work. If it doesn’t work for your doors, it’s not going to work for the engine compartment which has NO sealing what so ever.
Between falling into unseeable eroded sinkholes, the engine digesting water and hydrolocking (possibly destroying the engine completely), the after-the-fact corrosion that can take place in body cavities, wiring connections, etc., and the mold and mildew that can result from saturated fabrics, there are way too many ways that driving through seep water can destroy your car…and/or render it valueless.
You should never drive through water up beyond your rocker panels if at all possible. But if my life were at stake I’d sacrifice the car to save it. A car is replacable.