single turbo thread for an A Body
There's a few builds on here that are single turbos, and most just used factory cast exhaust manifolds. Have you done a search on here? Turbovan, dusted, subcom and toluene56 are all single turbo and there are more. Might have to make your own kit,
@Big_Al made my headers for my twin not sure if he's still building them. On some of those kits the waste gate flange or how they come off the header especially the ones 90* off will have crazy boost spike and harder to control.