What do you think a small block 350 or 307 in a 1980 Chevrolet Malibu

350 without a doubt better torque higher rpm

350 or 327 if you can find one. I have a zz383 in my 79 and I love it.

350. It has far more power potential.

its 350 or 305 same size block different stroke,if you can find a 327 even better.

The 350 is popular , easy to get parts for and you can find them all over the place, GM sells them as "Crate Motors" in various power outputs. The 1980 Malibu was equipped with optional 305 engine so everything will bolt right up. you can use the stock exhaust manifolds from the 305 and same transmission, the same intake and carb although you might want to upgrade to an aluminum aftermarket or intake and Carb from aftermarket, .

a 305 has a bore of 3.736in and stroke of 3.48 the 350 has a bore of 4.00in and stroke of 3.48 so its the same crank and rods just smaller pistons but it would b easy to bore the block to 4.00in and get 350 pistons

350 but you can stroke and poke any chevy small block and make a 400 if you wanted, id recomend a 383 stroker tho anything over a 4 in bore is pushing the thickness of the combustion chamber walls