The Microsquirt is SMD and comes pre-assembled, with a wiring harness for around $400. That will work with the Extra code. I agree the GPIO would be a pain with soldering, but I did the MS engine controller before they came out with v3.57 (SMD) so it isn't that hard. If you need any pages out of the 99 FSM let me know and I'll scan em. Fortunately I'm using an RH in my truck, so I added a governor pressure sender and let the MS control LU/OD. So far so good but could use some fine tuning.