I have heard that the baddest small block maxxes are .12 RB motors. Now I have never actually seen one but the dudes I know that are hardcore maxxers all agree that the .12 RB pullstart is the small Block king. X
Iv seen some real fast .12 maxx's. If you have the money for a good .12 you can make a fast race truck. I'm not talking an $89 engine but an RB like X has said.
I have a Collari .12 that I use in my truck from time to time. It has plenty of power. In fact, I have to be carefull with it so that I don't wheelie. It can be a bit tempermental, thus why I've been using an OS .15 CV-X, up until it blew up 2 weeks ago. I used my Collari at the race yesterday and had no problems.. ended up winning the main by a lap.. .
I did a straight drag race with another guy who has a OS .15 CV-RX in his truck and I beat him without problem. This collari they say has 1.25hp and revs up to 42,000 RPM. It's a beast, to say the least.. if only it wasn't so damn fussy!
Yes, it is finding that sweet spot that can be tough. It's very strange. I will default the needles and it will be running rich, of course. I start to lean it out.. and it starts to run better and better.. to a point. Then it starts to act rich again, lots of blue smoke.. slow acceleration. If I lean a bit more(about 1/8 turn) that is the sweet spot. Once I get to that point it hauls. Temps are in the 240 range. This had me stumped for a long time until I eventually figured it out. I can't explain why this happens, but it does.. oh well..