It might be backwards, I didn't install it and I haven't really looked at it since I got the truck. It was going to be set up for a carburetor, so maybe they thought it would help with departure angle?? Can be easily fixed if need be. I will probably pull it out and weld some fittings, fuel pump bracket, and possibly a new sump on it before runing it.

 

We use Magnaflow on race cars with no problem but I think they are too loud for the street. The 1000rwhp cars get 2 Weldon A400's on them.Extremely reliable and very,very quiet. 1 is on a Hobbs switch.