Automatic Transmissions
Info provided by Calvin of the Nivlac57 Youtube Channel
4L60E
This is by far the easiest solution for those who wish to run an automatic transmission. They bolt up, so no drama. The issue is 4L60e transmissions are notoriously weak. There are some who claim they can be "built right" and last a long time, but I personally like the cheaper and likely strong route of adapting to a TH400/4L80E.
TH400/4L80E
Once you have an adapter plate, the conversion to a TH400 is fairly straight forward. One thing you will probably have to do is redrill the flex plate to match the torque converter you plan to use. Additionally, you will have to make the appropriate length spacers to make up the distance created by the adapter plate. One more thing is making a hub adapter. For a TH400, you will have to make a custom hub adapter that makes up the distance created by the adapter plate. If you plan to run a 4L80e, an LS hub adapter will likely do the trick, since the hub on some 4L80E's is further forward.
Additionally, you may have to notch your bellhousing depending on how you did the adapter plate.
The following information was contributed by Emtech Motorsports
Aftermarket adapter plate from Emtech.Click for adater plate
The adapter plate is laser cut and cnc machined. The 2 side flanges can be used for mid engine mounting, which for high output (over 500 lbs/ft) takes the torque stress off of the LH engine mount. The plate is 3/8" thick.
Hub adapter - if you need a hub adapter and cannot make one - these are available from Emtech.
Starter adapter - this adapter solves the problem of having to modify a non-atlas bell housing to clear the starter nose. Its designed to work with a tilton starter. Available from Pohill Racing or Emtech.
