by tuning I meant getting some type of fuel management and getting it tuned by someone that knows what they are doing. Of course the internals will have to be done right also, if you are building the block up, you want new rod bearings and rod bolts, stuff like that. Tuning also involves adjusting the timing so its not all click and go. For instance, if you arent tuned well, you might be running too lean. Running too lean could overheat the motor or blow it at high rpms. There are a lot of other things to take into consideration when tuning, thats why people take their rides to people that really know what they're doing.