1989 Fleetwood Jambo Ford E-350 with 460 engine question

I have a 1990 jambo with the injected 460, and I've had the same problem.
Vapor lock.
It would do fine until I needed to climb a grade, she died on me a few times in the wonderful california heat (100+).

I added hood scoops to the hood, looks a little silly but it works great. I used dryer duct to help direct air over the exhaust manifolds.

I also removed the factory air intake going into the TB's and made my own. I also replaced my exhaust from the y-pipe all the way back.

I haven't had a problem since.