It sounds that you should be asking which mechanic to take it to
A tune up will not fix this issue
Something has changed - bad temperature sensor ?
Any check engine lights ?
if you got gearbox selector issues - shock proof aka - smurfs blood
Down load the penrite app and use the recommended oils
Good old australian made stuff
How many km's has the motor done ?
How old is the motor ?
If it's being stripped down - best to do what you can afford.
New pistons - decked block - valve guides - oil restrictor
My ac belt destroyed it self and i cant find what is the recommended size of the belt
Can someone list the belt sizes for the 1000 hp version of the ATI ballancer.