Well by wot I've read the muggy,aftershock and lst1 are pretty much the same as the lst2 and xxl share the same chassis, most other parts fit but lst2 and xxl have different arms...I have some of these and they look ALOT stronger than my ones but don't fit the bulk head and mounts on the lst1...gonna enjoy it how it is fur now and slowly build up the parts to convert. Forward only conversion kit I got off Ebay for 20 quid and is very easy to fit.....gives much more power I must say...bugger likes to loose screws so stripped and locked EVERYTHING!!! Can't wait to get it out there