wireing the haltec
 

i have to rewire my 93 but am also thinking off going with a haltec do i still need to rewire the main wire harness or does the halteck take care off that.

You are going to need to make some clarifications on what question you want answered. Are you keeping emissions equipment? What are your mods? There are 2 basic ways to do this conversion. You can piggy back with stock ECU or you can go full stand alone. The answer is in your answer to the above questions.

What spyfish said is correct. If you need to keep ALL of your emissions equipement you need the stock harness. If you think you can pass emissions with just your airpump (which is fairly simple) then you can use the Haltech harness.

If you are asking this question it sounds like you should just replace everything with the stock harness. Then if you want to go Haltech use the plug and play harness.