i have a holley pump and regulator connected to weber 48 ida. which gauge do you guys recommend ? 0-15 psi mechanical gauge to be mounted in engine bay off the regulator ? or the electrical one to be mounted in the car ?

huge difference in price though...mechanical gauge for around $50 and electrical for around $250

 

Heres from my experiance,
If your car is n/a not using nitruos,You dont need to spend the money and run one in the the cab of the car,

BUT if you do choose to,You need to run the Isolator kit.
http://www.autometer.com/cat_accesso...st.aspx?pid=39

Now inside the engine bay.

I run a inline adaptor that I got from Summit racing,for 1/8 thread gauge adaptor,and run a Russel,liquid filled fuel gauge.


I highly recommend to run liquid filled gauges if you run them in the engine bay.
1)The vibrations from a rotary engine,broke 2 of my gauges within a 3 yrs time frame.

You can also do a mounting cup,OUTSIDE of the car,ontop of the cowl.
You do not need the isolator.

There you go,
You have 3 options.