for 12K, you should be able to Buy a Gen 2.5, AND pimp it out.

for 12k I would have a Blown motor Gen2.5 with a 98 5.7 vortec, 4L60, and Terralow NP241 with a freaking 60 up front on coils.

87 Raider 4D56td v5MT1
31's..Basically Stock