Here is my write up on the swap,
Chevy Spring Swap. I read up on the pirate thread and it helps but I felt there where a few things left out. I tired to make things clear in my write up, such as the way to measure the distances etc. My father runs BJ spacers on his 4runner and my rear setup would be a great match for his front. Just note the shackle lenght and angle. I would recommend buying a Toyota rear hanger and placing it directly behind the stock one and using a similar length shackle to what I run. Also try to find a Toyota truck load leaf, the 4runner load leafs suck and so do the chevy's. You'll also need to think about a double cardon drive shaft.