your best bet is to buy a complete turbo long block. they are usually around 300.00 then freshen it up. I believe the turbo motor has different rods also they are forged. I was using a 4 cyl t5 @ 300 to the wheels. we are going to be upping that to 400/450 so we will see what they will take. I have broken them before behind a 351 but it had massive torque down low. since you already have the ranger motor why not torture it until it breaks