I have two of Mac Pinches body kits and have had alot of fun putting them together
A homemade brass chassis under the BRM. (not very satisfying as it is a plain flat piece of brass) A Tomy Ho motor was installed, due to size constraints, without much satisfaction. since the motor gets very hot and the car does not have any giddy up. Slot-it geare were used and the motor shaft was sleeved up to the correct diameter for the gears. Slot Classics slip on wheels look excellent on the car as well.
A Pattos chassis was purchased for the ALFA and a drive shaft set-up was used to get the motor further up in front. Now the driver would be able to be used in his cockpit as the mabuchi motors are a but of a snug fit and tend to occupy the space where the driver needs to be. BWA wheels are used along with Carrera turned down classic wheels as inserts. Tires are a combination os NINCO and CArrera.
Now that I am tossing around the purchase of another body kit or two, I am curious as to what others are using for chassis/motors/gears/wheels etc. I would appreciate any input from you scratchbuilders....especially a good chassis design as well.