diesel cutlass

I've got a 97 gmc 1500 that had a 4.3 in it that I am swapping out for a 5.3. Was told I need to use 4.3 oil pressure sensor and water temp sensor for gauges to read correctly. Needing adapters for them though to put them in the 5.3. I'm using hole for oil pressure at back of block on top and the water temp hole on drivers side head. Where can I find correct adapters for these? Thanks