Has anyone tried a 50mm VS a 52mm Fastman TB on their 360 to see which has the best low end torque?
How many miles does it take the PCM to learn the new TBsettings after you reset it?

 

Can't offer a comparison, but before I purchased my 50mm Fastman I asked by email what Dan (The Fastman) recommended personally for my rig. I have an '01 2500 5.9L that was ordered with the tow package. I wanted it set up to tow an RV. Dan recommended the 50mm just like is suggested on his site. Segue off the post for a moment -- I also asked about an opinion on shorty headers, as here in california need to keep it set up for smog. His recommendation was NOT to spend the money on shorty's. Probably more to do with the fact I want to keep my torque rating up.

With the 50mm over the stock it seems to have more torque for towing, especially up grades. Of course this is only a seat-of-the-pants report based on pulling a 27' trailer. Can't give you a report on the difference vs. a 52mm but I do like how it pulls.

I also am running a Flowmaster 40 out a single 3" exhaust, Volant CAI, Champion Truck Plugs, Accel coil and Napa cap, rotor and upgraded wires.

I hear numbers between 100 - 200 miles. My stock PCM seemed to be totally reset by around 100 miles of city/freeway work driving.

One difference I notice is that I wind up a lot quicker on the highway, which is especially nice when trying to pass on 2 lane highways. A LOT more get up and go. Hope I didn't wander to far off of your post.

Stats: 2001 2500HD Quad Cab SLT/Long Bed/4.11 Dana 60HD Anti-spin/4-wheel ABS/Tow Group/Heavy Duty Service Group

 

Shorty header would make that huge of a difference in torque, in combination with the 50mm Fastman? Did he say how much of a difference?

And with a 52mm I notice much more available get up and go over stock, best answer I can give, as I only have stock to compare from!

 

52mm TB is what I used on my 5.9 and loved it... you wont be disappointed...