I've done a couple Pinewood Derby's in the past and the block we were given for the car was a typical rectangular block of wood with no other cuts except the normal axle slots.
However, I am now doing an Awana Grand Prix and the car kit we were given for this race is the "Indy Car Kit" (http://awana.org/store/singleindycarkit/71677,default,pd.html?start=13&cgid=events-grand-prix) and this block has quite a few cuts to the block already. These pre-cuts are making preparation of the car more limiting/difficult than the standard BSA blocks.
Looking at the bottom of the block, the middle width of the block measures in at 1-3/4" and the end width of the block measures in at 1-3/8". The block width tapers down from the middle to each end. The width where the pre-cut axles are located is 1-9/16".
Assuming no additional wood would be removed from the width of the axles and a gapping for the wheels of 1/32" this would seem impossible to make the 1-3/4" clearance needed for the track (1-9/16" + 1/32" + 1/32" = 1-5/8"). The rules state that 1-3/4" is needed for clearance between the wheels, so I assume I need to allow more gapping between the wheels and the body. However, this would seem to be detrimental to the performance of the car?