Mixed opinions when it comes to stock/mild 304....low comp,baby cam & banana manifold you can't expect them to come alive without proper mods.
Even with just basic exhaust,airbox + memcal performance isn't as dramatic compared to a set of diff gears/stally/shift kit.
Another thing is not get caught in power figures.I've had cars with 'low' figures that felt quick & do decent times yet other cars pull decent dyno numbers but not so great times or feel that quick.
Ironically basic mods on efi stock to mild v8s were more noticeable improvement than adding a tuned memcal....only vehicle that has surprised me was my vp v6 ute after getting memcal done by Vlad