I know that back where the cooler tubes connect to the C4 the have tube nuts and double flared fittings but I have a question about flaring the tube and connecting to something like this (which I put on my aftermarket cooler) one that's attached. Do I need a single or double flare here, or does it not matter?
Allways double flare whenever possible. Line pressure in the trans can spike from time to time. You dont want a, prone to splitting single flare, to be the thing that takes out your transmission.,
I wouldn't think you'd need to worry about a double flare, I've run transmissions with nothing more than a double clamped piece of transmission hose splicing steel lines and never had a leak.
If its a standard SAE fitting...a 45 Degree double flare will be fine. If its an AN fitting...It needs to be a 37 Deg flare.
It should be, I think that's all the hardware store carries but I'll double check. I guess it doesn't matter if it's single or double, double is more secure. That's what I was gonna do but I had a moment of panic and thought I should ask somebody...