Which engines make the most power with upgrades, 250hp, 305hp or 325hp?

[Blacksdieselhp]

I saw where the 305hp engine made more power with upgrades than the 325hp engine. Is this entirely true? What about the 250hp engine, does it work better than the 305 with the upgrades or is the 305 the one to have?

 

[KLockliear]

They all seem to gain the same. Difference is where they started. The HO makes about 40hp or so more than the SO, and always makes AT LEAST that much more with the same mods.

 

[Chris Jewell]

I have seen some posts and dyno runs that show a 250hp motor gain more than a 305hp with a pressure box but the 305hp still makes more because it started with more.
Example 250hp may pick up 80hp
with box that adds only 50 or 60 hp
on a 305 but the 305 still makes more total power. I have seen this for PRESSURE boxes I don't know about timming and duration.