What spark plugs for 1963 230 engine

[dmjlambert]

After doing some research on the web using suffix stamping CD and date B36 block date casting code it seems I have a 1966 230 engine probably out of a Chevelle donor originally with Powerglide and A.C. and 140 horsepower. A few weeks ago I sprayed some penetrating oil into the cylinders through the spark plug holes. Today I took the belt off and made sure the transmission is in neutral, and tried to turn the engine by the flywheel using a flywheel turning tool and it does not budge at all, completely frozen. So, I need to decide what to do. I might pull the engine and put it on a stand and tinker with it, it would be my first go at something like that.

I have a friend who says I should put an LS engine and 4L60E transmission in it and I like the idea, but I don't know how to shop for one of those and know what I'm getting. It would also be fine with me to get this engine and 3OTT transmission going or get another L6 that works. If I get an LS engine and auto transmission, I will swap the 3OTT steering column for a used or rebuilt truck automatic transmission steering column. My goal is to have a daily driver that I will use less than 5000 miles per year, and whatever I get I will want to put air conditioning in, probably an under-dash unit. I plan to put manual front disc brakes on it at stock height and 5 lug bolt pattern and truck rally wheels. I'm not into high horsepower and hot rodding, anything that would get me to the grocery store and restaurants with air conditioning is what I want.

It has a 12 bolt open differential with 3.73 gears and 55 1/2 inch width between the brake backing plates, so it seems to be from the 60's as expected. I can get 5 lug axle shafts for that like I did on my 1969 CST/10.

Opinions and guidance welcome.