I have a 87' yj with a 2.5l. i've added a air intake system and i'm thinking of adding a throttle body spacer. All i've been able to find are for 90' on up models. Is there that much differance in the 87' to 90' throttle bodys and do you think it is help in proformance or milage? If anyone has any advice or experience in this I would greatly appreciate it.