mechanical fuel pressure gauge

Guys running "in car" mechanical fuel pressure gauges, how are you hooking them up? Do you have to buy the "isolator" as a separate kit? I'm wondering if I should have gotten a different gauge! Also, can you get a cowl cover that mounts a gauge for mustangs so you don't have to run the isolator? Thanks for any info!
 
Yes I had to get the isolator, purchased it all from Autometer. Ended up costing me about $20-30 less than electric gauge between the adapter to my fuel rail, the line running up to (#4 braided), and the isolator part number 5282 from autometer).

Isolator