[PAUL K]

I'm thinking if the performance of the engine was disappointing before the addition of 1.65 rocker arms, most likely the 1.65 rocker arms aren't the culprit.

My first thought was secondary lock out on the secondaries. Then a slipped harmonic damper and then exhaust. I'm not mentioning the manufacturer but I worked on a beautiful SD TA that was down 130 horsepower because of the "correct" looking exhaust.

If your familiar with using an "in car" vacuum gauge one might notice the vacuum won't go to zero under full throttle and will have a restricted reading when you back off the throttle when the exhaust is clogged up.

Then I thought maybe the OP is used to incredibly fast cars and a twelve second car seems boring.