Dave,
When you mentioned A/C compressor & 250 in the same sentence I had to read it twice. Then, I went to your photos and it was like sitting down with the master...
My C-10 has a 250 & Powerglide and although some might find it hard to believe, that is why I bought it. I'm older than dirt and Slow & Easy is how I drive. But the git-up-n-go has got-up-n-died.... A head-wind will hold me back to around 47 mph and if I hit a hill, 35 mph is tops.
I was entertaining the thought of changing manifolds, carb and distributor, but the total cost would be almost that of a V8 swap. I found Langdon's website and found his prices to be more than tempting. I see you've got his 2 bbl carb kit and my only question is the Carb Heat. I saw you plumbed the headers, but was wondering if ya had tried the water heat plate yet...?
Danny (aka: Rusty Nuts)
P.S. Thanks for you input on the A/C Systems also.....