You could run the MS3PRO for less than the cost of a race pack and then use a cheap tablet as your dash. Then when you are ready for EFI you already have a good chunk of the work done and you already have the controller.

Have you tried this? It sounds like a great way to go, and maybe could be an easy way to switch back and forth between carb and injection to get real world results and see which works better and if there is any more power to be had.

I ran a megasquirt MS3X(build it yourself version of the PRO more or less) for awhile with a carb. If you install the sensors you can log whatever you want.

In my case I used for ignition control as well. All my MSD stuff had failed over the years and since I was going EFI anyways I opted not to replace it. I used the megasquirt to control the ignition and datalog air fuel, coolant, and air intake temps. It was great for ignition control, my drag week average was about .1 faster than it ever had been and I had made no other changes. I just put 80 miles on it this weekend with the full EFI working and its easy and works great.

The ONLY thing that you would need to different if using it as just a logger would be the RPM signal. You would need two sensors on the crank to pick up RPM, one for the megasquirt, and one for your ignition. I am sure there might be another way to trigger it, maybe even off the MSD tach signal but I didn't intend to use mine that way so I didn't look into it. Check with the guys at DIYAutotune.com.

The MSD tach output to pin 24 will do it.

I want to say when I assembled mine that I need to do something different to allow it to work that way, but its been awhile.