I started this last summer by putting a brand new jasper stock replacement L98 in my '87 iroc. I spent all summer trying to figure out what was wrong with it because it didn't have the power I expected to no avail. Now summer is over and I am about to put her up for the winter so I broke down and took her to a dealership. They claim that the motor is in tip top condition and that they couldn't find anything wrong with it. Not that this is dissapointing, but my old engine with 80K on it felt way stronger before it started to go. Not to mention when I put the new motor in I added ceramic coated headers and some other go fast goodies. The car was modified when I bought it, so I figure mabye there are some high performance parts still on my old long block like an aftermarket cam that I didn't know about. What is a good way to check if it is a stock cam and are there any other posibillities to check for why my old engine would of been faster? I'm down right confused...please help!

 

Could be a lot of reasons why your new motor seems to lack punch. Could be the wrong cam
(too small ,big or not even a roller cam). Could have a lower compression ratio than the stock one. Could be that you have increased the airflow of the engine with headers etc and now the computer (TPI)is not feeding enough fuel to match
the new found airflow. (injectors, pump, computerchip etc) Could be a poor rebuild
(rings, valveseat seal). You can check the quality of the rebuild with a leakdown tester. You can check the lift of the cam by removing a rocker cover, set up a dial indicator on the rocker arm (over the pushrod) and turn over the motor by hand while reading the cam lift off the rocker. Multiply the result by 1.5 for valve lift.
Could be a problem with the trans (broken converter).