it will bolt up, but the transmission is different and the center shafts are different, the steering assembly is different, unless you've upgraded the driveline (knuckles, shafts, diffs etc to 3.3 spec or dog bones) it wont handle anything more than the titans. but the front and rear assemblys are bolt on but not brushless ready, just everything in the middle is different
Thats why it is better to start from scratch and build a complete project. Maybe using some of the stuff off of your old rig is ok, but with brushless power not much of it will hold up. With the power of a Neu 1515/1y or anything at that level the plastic parts just will not hold up for very long. Most of the T-Maxx and E-Maxx stuff are interchangable for the most part, except for the tranny.
It is nice though to see people making the change from Nitro to BL. Good luck with that and have some fun.