Transmission options. I needed to keep the automatic trans to keep the wife happy (and keep the car original). All 5.7 and 6.1 Hemi’s use the exact same bellhousing bolt pattern as any small block mopar. The only bolt it does not use is the hole at the 12 o’clock position (no biggie).
Lucky for me, the freshly built 727 in the car could be re-used for the same application. Not 100% sure as for the 9.5” converter (Dynamic couldn’t give me a concrete answer for the new Hemi’s) but I’ll find out soon.
The original starter location on a 5.7/6.1 is on the passenger side but luckily Ma Mopar notched the block so we can mount it on the driver side for our application (they musta’ knew we were going to do these swaps  )
Ok, to get the converter bolted up to the new Hemi I needed a SFI flexplate sold by Direct Connection as part# P5153753 which I purchased from Mancini Racing for $63.95. It includes new hardware to attach the flexplate to the crank. You will need to use the D.C. thin headed torque converter bolts to attach the plate to converter.
This beats the older method of cutting off the ring gear on the Hemi’s original flexplate and re-drilling the holes as needed.
By the way, the new Hemi is internally balanced, so neutral balance converters are a must.
An IMPORTANT note I must state here as I learned the hard way. The 6.1L hemi had a large I.D. pilot bushing at the rear of the crank which needs to be removed to allow the converter hub to properly register into the rear of the crank.
Due to the shape of the bushing it was rather difficult to remove. I could not find a puller which could get a grip to pull it out. The method I used was to use a carbide cutter tip on my die-grinder and cut the ring in 3 spots which allow the bushing to easily removed.

Now, since I am running a fully automatic valve body in the 727, I still need the kick-down/ Detent cable to still be attached to the engine. Problem is the newer Hemi’s have what is called “drive-by-wire” throttle bodies which essentially are electric motor drive throttle blade which is computer controlled by the ECM depending on throttle input from a sensor attached to the gas pedal or a throttle position box.
A throttle position box was used ’03-’04 Hemi Ram’s. It essentially is a box with a throttle position sensor in it. A throttle cable attaches this box to a mechanical gas pedal.
Later year Hemi’s would do away with the box by simply attaching the sensor directly to the pedal.
Tony and Chris Squier design their wire harnesses with both connectors so you can switch from a throttle position box to a electronic gas pedal instead.

Now back to the original dilemma. I needed a way to physically connect the detent cable from the 727 to the engine which has a motorized throttle body. Through the use of two Lokar cables, I was able to connect my original ’71 gas pedal to the throttle box as well as the 727 detent cable. The 727 cable is installed on the opposite end of the box so that it is pulled by the throttle cable on throttle and released on decal. Very ingenius. I learned this set-up from Tony Squier and Street & Performance.
Parts used: Lokar Universal 36” Throttle Cable and 727 Kickdown cable kit.

Had I used a manual valve body 727 or a manual trans, I could have simply used the newer electronic gas pedal for an easier and cleaner install.

As for the 727 trans dipstick tube, I originally had a newer type tube and locking indicator installed which I purchased from CRT. It faces forward and hits the rear of the right side cylinder head. A little tweaking of the tube to curve it backwards allowed me to re-use the dipstick tube and indicator.

And the last note on using the 3G Hemi with the 727, you can re-use the original trans cooler lines. There are no interferences with the headers or engine mounts and line right up to the new Ron Davis Aluminum Radiator.