You'll need all the accessory brackets and pulleys. Car probably started life as a 4.3 V8 260 ci Olds. I don't recall the VIN engine code. Not a bad engine as I had it in a 77 442 I drove daily for 6 years. Easiest swap would be to any Olds small block such as the 350 or 403. Olds 455 is slightly taller and may require different accessory brackets.
Check with the Trans Am guys as many of the 77-79 cars had the Olds 403.
Also check out the FAQ's pages at
www.442.com.
John