First time swap started

[dayj1]

Originally Posted by TrybalRage

1. Oil pressure. My truck had a 1 wire hookup, and the new motor also has a 1 wire sensor on the back of the block. I see a lot of people swapping sensors and needing adapters... why? Are these providing different signals?

Gauges and senders are a matched pair. All senders are not the same. So, you can't run the old gauge and the new sender and expect an accurate reading.

Originally Posted by TrybalRage

2. TCC lockup. I currently have a blue wire coming out of the firewall that used to go to the old th350 wiring, and it provides hot 12v until I press the brake. It seems like this is exactly what I need for the pcm, yet I see people all the time talking about splicing in relays. Will this not work?

Yes, it will work. You are most likely reading about swaps into vehicles that didn't have that functionality before the swap. It is something common to add into older swap vehicles.