Josh22855
Senior Member
I recently swapped my 8HP70 out for a 8HP90 on a 2016 Ram 1500 single cab, the HP90 trans was from a 2016 Hellcat (Thanks ebay!).
The bottom 2 bolts on the transmission bracket I moved back 1 and 1/8th inch and the 4 vertical bolt holes will have to be drilled out in order to bolt to the end of the transmission. I was not able to get the passenger bottom side bolt in because the bottom bolt on the horizontal bracket was in the way.
You cannot use your torque converter from the 8HP70 transmission, the 90 input shaft is larger. The Flex plate does not have to be replaced.
You may also want to explore other bolt options for the output yoke on the driveshaft, there is absolutely no room for a socket to fit on 2 of the bolts.
You can see each part # in turquoise in these photos, I did not get a photo of the dust cover, you will have to drill out a hole for the starter. The factory dust cover AND factory starter will not work on the swap.
Hope this info helps out the next guy.
The bottom 2 bolts on the transmission bracket I moved back 1 and 1/8th inch and the 4 vertical bolt holes will have to be drilled out in order to bolt to the end of the transmission. I was not able to get the passenger bottom side bolt in because the bottom bolt on the horizontal bracket was in the way.
You cannot use your torque converter from the 8HP70 transmission, the 90 input shaft is larger. The Flex plate does not have to be replaced.
You may also want to explore other bolt options for the output yoke on the driveshaft, there is absolutely no room for a socket to fit on 2 of the bolts.
You can see each part # in turquoise in these photos, I did not get a photo of the dust cover, you will have to drill out a hole for the starter. The factory dust cover AND factory starter will not work on the swap.
Hope this info helps out the next guy.