Wide frame vs narrow frame -wheel base?
 

can anyone fill me in on how much wider the axle/rear wheel base on a 149 would be then on my 100? Thanks in advance.

The rear on the 149 is not any wider. The WF vs NF difference is in the frame rails where the engine sets.

I've never actually had a tape measure on either of them, but I don't think there is any difference in the width of the transaxles, the overall width difference comes from the rear wheel width/offset.

For the front axles, the Narrow Frame front axle and spindles are a lot narrower than the Wide Frame front axle and spindles, if the correct wide front wheels are installed on each, the overall width ends up being almost the same, because the wheel offsets are reversed between the two.

Not sure if any of this answers your question or not.

To add....the only thing that comes to my mind is the tire width of the rear wheels. 10.50's vs 8.50's. The rear end and axles would all be the same.