I used a Hotwire harness in my '68 Barracuda 5.9 conversion. I skipped the computer controlled transmission and went with a 200R4 with bellhousing swap. All my gauges are rebuilt factory units keeping the harness a simple plug and play affair. I did use the 2000 EFI injector connectors and an OBDII ECU for a 5 speed Ram pickup.

My tuner sends me tunes to download into my SCT tuner and adjusts them based on my wideband readouts. After reading all the tuning headaches and hoops guys running other systems have to go through, I'm happy I went with this plug and play system. It's great.

Building an EFI fuel system has gotten a lot easier over the past few years too.

1970 Plymouth 'Cuda #'s 440-6(block in storage)currently 493" 6 pack, Shaker, 5 speed Passon, 4.10's
1968 Plymouth Barracuda Convertible 408 Magnum EFI with 4 speed automatic overdrive, 3800 stall lock-up converter and 4.30's (closest thing to an automatic 5 speed going)