There is a guy on the Facebook group for the 8HP trans, he installed the 8-spd trans behind the 318 in his 88 D150. The 8HP bolts right up to the Hemi/318/5.2/340/360/5.9 block. He used a flex plate from a GM 4L60, and drilled it to match the 8HP torque converter. Then he bought a custom harness from Sound German Automotive, he said it was a plug and play setup. The 8HP needs a signal from the TPS, tach signal for rpm, and a connection to the reverse switch. He said after some test driving the TCM learns the setup and everything worked great. He even said his D150 now gets 22mpg on the highway.