I'm wondering if the plastic will do something to keep the intake air cooler in the summer and warmer in the winter?

That is provided I do a good job of gathering cold/warm air depending upon the season.

Also does anyone know if the "van" units are more of a low profile then the "truck" ones?

There won't be any significant effect on air temp at the carburetor neck depending on metal vs plastic. I changed from a metal one to a plastic one on my '89 D100 years ago because the plastic one was more nicely made and I'm a geek that way.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

Thanks Dan,

I assumed that dodge went to the plastic for emission or drivability improvements. Maybe it was production costs, or a different supplier?

Anyway the metal ones are more easily found, and easier to adapt, so I guess that is the way to proceed, tho the plastic ones are nice!

Yup!

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.