hey guys im new to the forum just looking for some outside advise

i have a 350 factory bore honed, new rings, new bearings.
stock heads with valve job and resurface casting #10110810
high swirl intake ports.
lunati cam part #60101 .454in .468ex 213* 219*@.050 256*/262*adv LS112* 108*cl
but i have valve springs from a summit cam part#pl11p0414sr with 204*/214*@.050 .420in .442ex
holley stealth ram
accel 24lbh injectors
kirban perf afpr 43.5psi
msd blaster coil
commander 950 ecu
stock manifolds
custom ram air


with the stock ecu i ran 15.76s at like 86 87 mph consistently
the motor seems to run out at like 4500rpm it feels funny when it gets to that rpm but no unusual sounds or anything and in neutral it will rev to like 5500 no problem. since i have changed to the commander 950 and now run 15.20 at 87-88mph consistently still runs out at 4500rpm though
i have put a lot of money in this motor and it still runs about the same times ive gained close to a half sec but still?

oh i have a 700r alto red race frictions
kolene steels
3-4 9 clutch pack
corvete servo
custom shift kit
2400 stall

auburn posi
richmond 3.73s
mosser axles 28spline

any thoughts?

 

Headers and a free-flowing exhaust.

 

i do have 3in single all the way to the muffler.
i was thnking the problem was the heads or the valve springs


just added a dynotune 150 shot shes on the bottle for now goin to th track on fri