i have a 90 bronco with the 351efi. i would like to change to a dual exhaust, but am not sure if i should split it after the cat or go with some shorty headers. also if i run the pipes out under the rear bumber will i have a problem with fumes in the truck? please help?

 

If you want gains in power and torque, run true duals with an "H" or"X" pipe. If you have inspections where you live, you might consider a pair of high flow cats. If not, cut 'em off. Headers aren't really necessary, but if you want even more hp and torque, run 'em. You might also consider a pair of Flowmasters-nice tone, good flow, and they come in all flavors from mild to wild(in volume).

 

if i run the duals with the headers do i need to do anything to the motor because of the exhaust? i was told i might have to put in a computer chip or something?:-X11