I have a Vintage Aire in my '62 C10. I do have the 327 SBC though. I've been very happy with the unit. I installed it about 6 years ago and it was a clean install using the factory controls already installed in the dash.
I had to specify V8 when I ordered it. I know they make the mounts/brackets for the I6, you just have to specify what you need.
As for the power, I can't comment from experience, but have heard it is functional, but will take a bit of your power on the 235. I know others have done it. Maybe they can comment on their own experiences.
