wiring harnesses
Going from a 5-pin ecu to a 4-pin ecu is a direct swap no wiring changes necessary. That fifth pin and the assoicated wiring is not used when you plug in the 4-pin ecu. You can still use the dual ballast too.
For and egine compartment harness Evans has the best prices
http://evanswiring.tripod.com/evanswiringharnesses/ , they don't have a under dash harness the last time I looked.