Choosing the best 5.7 engine and Transmission

I agree with the 09 and up unless the heads have been rebuilt as the earlier engines have valve seats that liked to drop. If buying used I would recommend at least a cam and lifter swap depending on the mileage of the engine. I have seen the lifters fail as early as 60k miles. I would do the MDS delete at the same time. If using a A518 trans (or similar) you need to have some kind of throttle linkage to the transmission for throttle pressure. There are a few ways to accomplish this. Also the factory ECM must be run with an electronic DBW throttle body (as far as I know anyway). You could go with Holley injection as they have nice setup for the Gen III Hemi's but they wont control the VVT so if going this route you will need to lock out the VVT but you can run either a regular mechanical throttle body or an electronic DBW one. Also food for thought is the 09 and earlier ones don't have VVT so you don't need to worry there. Also with no VVT there are many more cam choices. I wouldn't be too worried about the head flow unless you are really going aggressive as the early heads already flow 270 cfm stock and can be improved quite easily. The 09+ eagle heads flow 330 cfm out of the box....Oh and Holley has no transmission support Mopar transmission control as of yet but it is coming as there is a drop down in the software but no options there to choose so if you are wanting to run anything more modern than the A518/A500 the factory controller is the way to go right now (I know there are some stand alone transmission controllers in the works). Megasquirt is an option too, it controls VVT but not electronic DBW throttle bodies as far as I know yet.

That's all I can think of right now. I'm working on my own Gen III Hemi swap so I'm in the middle of this right now too. I was going to run a rebuilt 05/06 5.7 based stroker with Holley injection but I got a very good deal on an '18 5.7 hemi with 10k miles on it. I will probably go with the factory controller and tune it with HP software.

Garth