Originally Posted by hotrodder
Do you have the actual cam spec's? If you run too big of a camshaft, it can and usually does hurt overall performance gain. If it's a little more than factory, then it will bump the power up (how much I don't know). Usually, people go to a bigger cam after a cold air intake has been put on, bigger throttle body, perhaps even a throttle body spacer, and a better flowing exhaust system.... Then the other factor is the heads... Will they flow enough to make use of all the more flow in air into the motor, and get it back out? Depending on the cam in question, you may even have to upgrade valve springs and retainers... It kind of all depends on, well, everything... Let's start off (since I don't know what you're dealing with in total) all your currently running, and the actual cam spec's in question....
The cams he is looking at are all based of the H/O cams which are factory cams. The H/O cams are on a 111 Center line while the standard cams are based off a 115 center line... These have been a popular upgrade ever since I can remember dating all the way back to 2002... So there is nothing to worry about other then gaining about 20RWHP with them. They would work real well with the 2008 Intake and a 70MM throttle body.
Throttle body spacers are useless on a Multi Port Fuel injected engine... think about it. They are said to help "Atomize" Air & fuel by "Spinning" the mixture... but on a Multi Port Fuel Injected engine the fuel is not introduced until the end of each intake runner... so that means only air passes through the spacer... and it has to travel a minimum of 24 inches before it ever sees fuel. I have also seen Throttle body Spacers LOSE performance on the DYNO... here is a picture of a spacer held to the back side of a STOCK throttle body... look closely as you can see the INNER diameter is much much smaller then the throttle body diameter... This is a restriction!
SPEED SAFE, AIR RAM