I had a leash sportsman board in my car and then beginning of 2023 I purchased the K&R complete wiring kit. The leash was nice but the K&R I like much much better. For the simple fact I only have to plug the switch panel into the relay board and everything goes to its appropriate accessory.
You’ll love the K&R Korie.
There’s lots of little details that can go into wiring. I would say a lot of important things were touched on by other members like alternator size and cable size.
The biggest thing I would touch on is the way to ground the car is very important. Personally, I ground the battery to the chassis. Then run a ground cable from the battery to a common post inside the cab of the vehicle, close to where your relay board will be located. Then run a ground cable from the common post to the engine. Then ground engine to chassis. I would ground both cylinder heads to the chassis. Also be sure to ground the case of the alternator to the chassis as well. Some go as far as grounding the starter case to the engine or chassis and ground the transmission case to engine or chassis. Let’s just say if you have the car properly grounded, electrical issues will be easily identifiable as mostly all issues I’ve ever experienced were either ground related, or a poor connection. Msd ignitions are VERY ground sensitive.
Do not run your crank trigger/distributor pickup wires near any high voltage wires such as alternator charge wire or coil wire. They sell shielded distributor/crank trigger pickup wires so that electromagnetic interference will not occur. Meaning, if your distributor pickup wires are ran next to say your alternator charge wire, the alternator wire can cause interference to the pickup wires, causing all sorts of grief.
There’s tons of other things you’ll come across Korie but nothing that the members on here can’t help you out with.