I'll throw in another vote for the Tower 75! I have an EVO 60 size and gave up on it. I have tried to help flyers with Super Tigers and have no use for them either. I have an OS 61. Its reliable but the power is disappointing especially when you consider the price. I have helped other flyers with their Thunder Tiger engines and have no complaints about them. After trying my first TH 75 engine looking for reliability and good power I was hooked! I use them in all my warbirds because I won't trust any thing else. Hope this helps.