Hi Crius. I took a look to your videos, did you made them? I thought those were Gary´s-Max U(something) videos.
About the Panzer IV, Im using the asiatam lower metal hull, and the sprochet is in correct position (not like que Heng Long, this is rised up about a centimeter) but the bad thing about is that I can only fit the low profile two speed gearboxes, with that tiny motors.
I just added a home made photo of them:
I had no time to test them yet, so I dont know If they will have enought strenght once added all the weight and anyway are very very loud. If the stock heng long motors are 380 this ones maybe 290 or something. Correct me if Im wrong.
Returning back to my old-but-trusty Panzer III, well, I´ll think I´ll follow Richard Johnson´s route and I may buy those V2 Taigen Gearboxes.
Im very dissapointed with that Mato 4.0 Gearboxes, But still like the good look of them, and the possibility of using larger motors: This is a comparison that I made. The black ones are the asiatam´s low profile gearboxes, the grey is the stock heng long and the red is the upgraded heng long that has TONS of speed and torque.
I dont know, maybe a possibility could be to try those 4:0 gearboxes and if the quality doesn't fit just send it back to the retailer and ask for a refund.