I like the PTC 9.5in non lock up converters. They spool big turbos easy and are very efficient up top as well as very durable. You will need aftermarket axles with at least 30 splines and a 30 spline carrier or spool. A lockup unit meant to be locked will cost a lot and performance is not as consistent as the 9.5in PTC converters. A driveshaft will be a good investment if the car is going in the 1.40's consistently. Which it should be if your going to be be going low 10's or faster. You will need more turbo for that though.