Since I no longer race any more I have put in a O.S .18cvr and it hauls. You can just abut wheelie all day long if you so choose. Very fast on the bottom end But not quite as fast on the top end as some of the higher end .12's. The powerband is smooth from what i can tell. But the thing is there is so much power and so little weight and traction that you really cant tell even with the engine pig rich it still will spin the tires at will. But there is a down side to all this power when switching from a lower powered engine is that you will find the fuel tank to go down very fast compared to a smaller less powered .12 or .15's. I slapped in a .15 in my xxx-nt the one day just to see how much of a power difference there was from a .18 to a lower powered .15 and it was a big difference but the .15 still overpowered the truck. But the biggest difference was in how long the fuel in the tank lasted. The .15 sipped the fuel while the .18 chugged the fuel down.

If you want power and some longer run times a higher powered .12 or .15 will still over power the truck and giving you a lot longer run times. But if you want insane power then a .18 will do the job but you will have to buy more full more often.

I hoped this answered a lot of your questions but if not just get back to use. And i will try to answer those Q's