heres the deal..i have a 98 z28 with a 01 block bla bla bla...i used to have home ported heads that flowed 10 cfm above stock along with a ms3 cam 237 242 603 609...i spun a bearing so i decided to put the motor back together with stcok 241 heads and a big cam..the cam is a 244 250 608 625 108..now the prob is the old heads and cam set up made 391hp and 430 tq and the hp curve was great..so i put the motor in run it for a couple of days and decide to put it back on the dyno..the car with big cam stock heads th 350 8 inch 4600 converter ls6 intake pully tb long tubes duals and a new tune wich is the same stuff that was on it with the heads and cam set up only made 370hp and 460 tq...the prob is the hp curve goes up goes flat dropes down and loses 5 hp then goes back up and gains the 5 back then goes flat till 6800 where i shut it off..so basiclly from 5500 to 6800 i only gain 3 to 4 hp..down low the stock heads make 15 more hp over the heads and cam set up the falls off ..ive checked the valve springs thinking maybe they are weak but they checked out fine..ive put a tech 2 on it and everything is fine...do you think that maybe this cam juss sucks or is to big or what im lost...i would love any help..
thanks

 

Start off the diagnosis by changing the valve springs to a heavier rate set...

Ed

 

from the testing i dont need a better one i tested all 16..everyone was fine..the seat pressure open all that was good..

 

What valve springs are on the car?

A graph of the dyno run would be helpful.

 

prc springs ..i dont have the dyno graph..but like i said it goes up flatens out drops down 5 hp and goes back up and then flatens out..ive showed texas speed the graph and they have no clue...im lost any suggestions