Need Headers for 78' Elco

I would like to know what set of headers (LT or shorties, don't really care) I went through 4 different sets of headers and had no such luck, 2 of them I called the manufacture to verify that it is applicable for a el camino that year. The engine is a 355 from blueprint and if this helps, I have this crossmember http://www.summitracing.com/parts/sum-770300

I left out some details that would help, the heads are vortec http://www.summitracing.com/parts/mll-h8002k, they are ab it wider, the exhuast ports are standard, but I have tried some headers that are supposed to fit the year and model, some where tried to fit and some just straight up were not going to work. Here is a list of headers that I tried.

68318
68640
Both of those the passenger is constantly hitting the sidewall
I have 68608 on the way
I am also going to try to wing it with these 11500flt, hoping that may fit.
If that doesn't work, I'll try the 31104FLT (the number 8 pipe concerns me though)
If I can't get anything to work, I better be ready to spend $$$$ on custom headers.

If I do find a set of headers that "fit" without concern of banging against something, I will post model number and mention anything that needs to be done if someone gets this http://www.blueprintengines.com/ind...g/gm-355-main/item/gm-355-dressed-bp35512ctc1 (BTW the dyno sheet that came with the crate reported 420 hp @ 5400 and 436 FT/Lbs @ 4100)

@lilbowtie, with the Schoenfeld (186-3?) was there anything you had to do to get them to fit? I think the heads on mine are a little bit wider which is why I am having issues with many different sets.

Got these to work (68608), just went right in. With minor adjustments.

Thanks for the input.