[TwistedCopper]

You can open up the intake one of two ways, either removing the stock airflow restrictor in the stock intake tube and replacing the filter with a "drop-in"K&N, or just replace the whole works with a K&N (or other brand) cone intake. Another mod would be a cat-back exhaust like Gibson , Borla, or another brand.

Getting rid of the stock mechanical fan and replacing it with an electric fan can give 5-10 HP. YOu can use either a junkyard fan from a Taurus or a Flex-a-lite Model #475.

I don't know if using a 4.0L's throttle body would work on your '88, as yours is throttle-body injection as opposed to MPFI. Maybe someone else can answer that...