Just got finished installing some SLP headers (took about 9 hours) and when I took it out for the test drive, it was idling really rough like it had a huge cam in it and also it felt like it didn't have power brakes. Had to put the ****er to the floor to get it to stop. Checked for pinched lines and would cause. Thought it might be a vacuum leak but not for sure. Any suggestions would be great.

 

Have you checked to see if the vacuum hose from the plenum to the brake booster is in place?

 

Bingo! My most forgotten line to replace.

 

Same here and the funny part is that as far as vacuum lines go that one is huge.

 

Yeah, but it is in the way of so many things that you are always pulling it back off for something, then forget to put it back once you finally get to what you were after.