I am replacing the stock exhaust pipe on my 89 4.9L and have a question. I am considering using longer pipe from each exhaust manifold before running them into a dual inlet convertor under the truck. What affect will this increased length have? After the convertor there will be single 2.5 " pipe to a Dynomax muffler. I do not want any decrease in torque as this truck is used for towing. Is this configuration a bad idea? Thanks.

 

Dosen't at all sound like a bad idea, I do remember seeing a pic on here of a set up as you described. Not very sure if it may decrease the torque, but it will flow better.