The Max ST hasn't been produced for a long time I just rebuilt mine. It currently has a HPI Superstar 15 with RD logics dual exhaust and other parts. It doesnt run or look like a duratrax any more...... Soon to be droped in is a HPI 25 out of a Savage. Oh and I need as many parts as I can get off of that cause my buddy has the same truck with a TRX 2.5 currently being rebuilt...... I turn a Duratrax into a DuraPI.