Motor selection for 30 "A" truck

My father and I have been disscussing what powerpoint I should use in my truck. I want reliable, fuel efficent engine that sounds good and is still sporty.
I am most familiar with the 289 paired with a C4. However my father claims that the 289 is too narrow and long for the engine compartment. He is pushing for me to use a "y" block, and has 2 of them out of cars and ready to go. He also has three flat head blocks that I could have, but he claims that I would be investing about 6 grand inthem to get them to look purdy and run right. Any suggestions for going true blue?

Idealy I would have a 289, C4, 9 inch w/ 4 11's

i like the y block idea myself, but i think the 289 would be good to