Stock for stock a V8 is a better choice. You won't have to use premium fuel and it will have all the torque off idle. To get good power on pump gas (300+ rwhp) out of an L28 turbo you'll need a bigger turbo, injectors, intercooler, standalone ecu, and a clutch that will hold it. It will add up quick. Those parts added to the V8 will make twice the power of the L28T.