I am upgrading to a single turbo and I was wondering if I should rebuild the motor now or wait till it blows. the motor has 67xxx miles on it and before i took the turbos off i had good vac. around 16-19 inches.. what would you guys do if you were me

Do a compression test. If you can afford it, its best to rebuilt it now. If you pop an apex seal, chances are you will damage your new turbo as well. If the motor is still strong and just looses compression of yuo break a coolant seal, you can always rebuild it later.

Likewise, If you have the money an dcan afford it its best to rebuild and even street port the engine before your put the turbo on the car.

I'd rebuild it. You'll need to have it pretty damn stripped down to build the fuel system, run the oil lines, and remove all the worthless **** in there when going single. Good luck!

thanks for the advice, pulling the motor this weekend.