47-55.1 exhaust drone?

[leegreen]

My truck has a 250 inline 6 in it. The exhaust I built exists under the running board in front of LR Fender. the muffler and tailpipe are 3" which is overkill for a stock 250 but I had the muffler and some u bends on hand.
I like the look of the exhaust poking out under the running board, but may give that up to make the truck quieter.

There is an annoying drone at at 2500-2700 RPM I'd like to eliminate. A sound spectrum analyzer on my phone shows the spike in DB with the drone is 173hz
Some options I am considering

1) extend tailpipe out the back of truck. This is the high effort solution as I have a c10 trailing arm rear suspension to snake it around. but the longer pipe will probably make it quieter overall which is not a bad thing.
2) make a silencer to stuff into the tailpipe. This is the low effort solution
3) make a 1/4 wave resonator J pipe 20" long
3.5) extend option 3 to be a muffler bypass with a butterfly valve at the 20" point so I can make obnoxious noises on demand

Anyone have any experience or suggestions to share?
Here is what the exhaust looks like now and where the J Pipe might be added