Curt,
Two options.
1) Simply re-pin your existing harness and add the wiring for sequential injector firing and MAF. It's not as hard as you think.
2) Get a male and female 60-pin end and make a jumper harness that goes between the truck's underhood 60-pin end and the PCM. Use that jumper to effectively re-pin the truck's harness to the new VEX1 PCM. From that jumper harness you can sprout the sequential injector wires/plugs, and also the MAF plug. As far as what to do for the injector harness, all you'd need to do is unplug the factory injector plugs and plug in the new injector plugs. This system would not touch a single wire under the hood of your truck and you cuold remove it to go back to stock in a very short time.....would never know you've been tampering under there.
This is the route I have taken.
However, I do have another Lightning harness that I intend to re-pin as a VEX1 setup and make it look "factory". If you're interested in doing either, shoot me an email and I'd be glad to spill the beans...
Later,
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- Kevin
Black '94 #907