Need help choosing heads

[Mach3107]

My dad and I are going to build a small block for his 71 roadrunner.
I have these heads that came off the 360 that was in 78 1/2 ton.

They have the "X" on them so are they X heads? Here's the numbers.

top side: AAWJ340, 03249, 2531894 D

under side: 2531894 - D

We are looking to build a good power/price motor, should we go through these heads or just buy aluminum?

thanks

 

[Coronet 500]

I find 2531894 casting number as a 68-71 340, 63.0-73.5cc's.

 

[67 B-body]

My vote is a good flowing out of the box aluminum head.
Besides the benefit of added flow and decent chamber size and shape "efficient", they also allow you to run on the average of a full point higher in comp. and have the same drivability with the same octane level of fuel as a cast iron head at one point less in comp. The aluminum is thermally inefficient, and is why this happens.