The H-Pipe is not difficult to install and is a common job for muffler shops.

The H-Pipe on my 32 is for sound attenuation problems and not so much for performance.
It's too far back for performance requirements, but it took the low frequency resonance out of the exhaust system.
Get one installed when you do the exhaust system.

The 32's exhaust system is 2 1/2" and the H-Pipe proper is 2 1/4".
Using the next size down pipe makes things easier as far as the cutting and welding goes.

I had a pair of Walker's Turbo muffs with glass packing on the car for quite a while.
They sounded good and after about 8 years they got a little noisy.
Two Chamber Flowmasters were installed and after a little running around with them, the H-Pipe was installed.

I have three chamber Flowmasters on my 2002 Ford F-150 SuperCrew with 5.4 liter engine.
They sound great, very much like a longer glasspack from the good ol daze.

If the muffs end up under the chassis on my 31 I'm going to see if the three chambers will fit.

It ain't the noise, it's the music....