TLT crawler - Finally got started.... (1)

I finally got my bum in gear today and started on my first crawler which is based on a TLT. I've got as far as the axles and after listening to Desmond Dekker singing 'The Israelites' i feel all hyped up and ready for more. However, frustratingly i've yet to receive many vital bits and pieces such as the chassis (can you guess which one?) as they're all still in the mail. I just hope i get all the parts i bought. I've got these uber-cheapo Traxxas (fronts #3675) rims attached but the threaded part of the axle barely pokes out making it difficult to put the wheel nuts on, I wonder if this is normal and whether the wheels will come off while operating? Let me know if you can help as i feel pretty lost building my first crawler. And what's the point of narrowing rims? All these damn questions..... Anyway assuming i get all the parts i hope to get this more or less done in a month or two.