I looked into going from a slant 6 to a small block and doing the swap correctly, I believe that it was going to cost me around 15-20k, maybe more as l had to get the engine, transmission, rear end. I figured that since the brakes would also need to be changed out I figured on changing the k member assembly. It's thing's like motor mounts,radiator etc that raises the cost of doing a v8 conversion. If memory serves me the entire cost including the car would've been around 30k. That may seem unlikely but like I said it's the odds and ends that add up quickly.