Engine swaps are common in motorsports to go faster for not a lot of money. I have a few LS1 swapped Nissans - and know a few other people with them too - and there was one big thing about them that always annoyed me: the gauge cluster.
If you put an LS1 in your car, your gauge cluster stops reading your RPMs and speed correctly. There are some options you have to fix this:
1. Buy a standalone wiring harness and ECU. I don't like this option because it's expensive ($5000+ after a tune) and it doesn't solve another problem I'll get to later
2. Use an OBD2 reader and mount a tablet somewhere to read these values. Not only is this ugly (I don't drive a Tesla) , but the tablet then dies at some point if you don't drive your car often, and you have to wait for it to boot. This also can't work for a pre-OBD2 engine swap like a Miata 1.6L to 1.8L.
3. Auxillary screens like a PowerTune. These are less offensive than a tablet but are still ugly, take a while to boot, and still require you to have your OEM cluster for other things like warning lights, turn signals, high beams, etc. (a standalone also has this problem)
4. Dakota Digital Converters. The least invasive of all the options, but still requires cutting your wiring. I am also yet to get one that reads just right... my tach bounces and jitters in places, and I've heard of others with this problem.
On top of everything above... the first car I ever LS swapped had a cable driven speedometer, whereas the LS1 (and many other cars) use a speed sensor. Not only did I need to install a Dakota Digital in my car, but I needed to hack up my factory wiring further to fit a different gauge cluster from another car with a speed sensor input. It was a mess.
So, I decided to come up with a solution that solves all of those problems: