While waiting for my yellow panels arrive, I am going to do comparison between the original set & my studless build, so I will build the set & rebuild the studless one more time.
Original set on the left, studless on the right.
The mounting for the studless got extend 1 stud at each end, so it add 2 studs to the total length of the engine.
The 1x8 plate replaced by a 6L axle, the mounting bricks replaced by 2x Axle and Pin Connector Perpendicular Double (part #32291) & an Axle and Pin Connector Perpendicular (part #6536) at the center for the drive shaft.
The engine mounting consist of 2x Liftarm Thin 1 x 2 - Axle Holes (part #41677) connected by a 2L axle with 1x Liftarm Thick 1 x 2 - Axle Hole (part #60483) in perpendicular way.
The driving gear also replace with the new 1x Gear 20 Tooth Double Bevel (part 32269)