Originally Posted by captain78
What's the deal with lower intakes what do they do. Anything or are they just spacers connecting upper to the block and heads. I was wondering cause I know a few people that changed there upper but not the lower. Somebody sheaf some light on this for me
The lowers adapt your particular upper to the intake ports on the heads.
Not all uppers fit all lowers, they are different and some flow significantly better than others.