Wheel spacer question

Ebay might be a decent place to look too. Some of it might depend on how thick you need, but from the sound of that backspacing sounds like you might need a fair deal. I got a set of 1.5" thick ones off of Ebay (4.5 bolt pattern) for a really good price that have held up well, but I'm not sure what they had for 4", you'd have to look