but please don't hunt my cat...
As regards your 66 project, it sounds like your starting out with a good heart. It would be mighty fine for you to partner up with your old Dad and get his 66 spiffied up once more. My Dad's sentimental favorite was a 55 Belair that he had a a young man just back from the war (the big 'un-WWII).
I have dreamed of getting him an updated Belair as a gift but time and money haven't been on my side. Besides, at 81 years of age with failing eye sight and failing health, I don't think he would be able to drive it much. So, my advice is...since you already have the truck and many of the parts you will need, jump right in there and get to work.
I like the Chevelles too. My first car was a 66 with a 283, 2bbl, powerglide. It wasn't near as fast as my buddies 289 mustang so, being the D/A kid that I was, I put a 4bbl intake on mine and bolted a thermoquad on top. That poor little 283 would just drown when I gave it the gas until I got it over 30 mph. Never did beat my buddy and his mustang but that ole chevy sure was bullet proof. At least until an old man in a big Chrysler pulled in front of me as I was hurrying back to high school to avoid being caught for skipping gym class
Totalled my chevelle and coach wore me out the next day.
Them were the days.....