Unless you know alot about rebuilding these particular lower ends then i'd suggest you go with a simple stage 1 from a reputable vendor/builder . the money you save by doing it yourself may come back to haunt you and it's pennies compared to the peace of mind and warranty you will receive . There are certain areas of the block that need to be addressed by a good machine shop that knows what those areas are . A good builder will also suggest other parts needed to accompany your build that you may have overlooked . My .02