The small block may make more power or torque but the LS will almost always be more efficient. I don't know this to be true in all cases but I think if you compare the cost of each HP per dollar I believe the LS will be cheaper in the long run because of the edge it has with efficiency. It is just a better design overall. But that is not to say there are not plenty of high HP small blocks out there. It is a proven design and has been a staple in hot rodding for decades. No one will dispute how well it can do. But back to the HP per $ and the LS may come out on top.
If you are going by just displacement then how do you compare? Stock VS stock? Say a 327 VS a 5.3 LS because they are close in size. Or a LS6 VS a LT1 350, the LS6 was factory rated at 405 HP in stock form out of the ZO6. The LT1 was never rated that high. Throw a cam and good set of heads at the LT1 and you will get there, but do the same thing to the LS6 and it will beat the LT again. So how do we do an equal comparison?
One way would be to use all factory parts, even the GMPP heads and cams. The LS will still come out on top.
I am not an engine builder or expert by any stretch of the imagination. So if I am wrong here please go easy on me.
