dropping down in front of motor is semi reasonable option but the audacity of the upright setup does have some intrigue. sweeping up behind a roots blower with flapper valve on top would definitely be a statement. Probably a literal headache to drive. lengths isnt really something thats able to be controlled with them, just being a close to even as possible. also some are 8 to 4 to 1 for packaging. a flat merge collector would help packaging although next to no information is available on them other than it was tried and dropped.
Seth

Designing a set of headers for a particular combination is a rabbit hole subject.  First and foremost, the chassis that the engine is going into presents a number of challenges in getting the tubes fitted properly and still keeping tube lengths and placement as they need to be.  There are several different designs for the headers including short tube, long tube, equal length, try-y, unequal length by design, stepped, 180°, 4-1, 4-2-1, etc.  8-1?  And then there are merge collectors which is another subject within itself.  If using a full exhaust system behind those headers, then that exhaust system itself negates some if not all the benefits of some of the header designs in that the reverse pulses (reversion) within the headers are disrupted and no longer acting in the manner that’s the most efficient.

Here's a picture of the headers on my roadster which have the tubes orientated such that the exhaust motion within the collectors is clockwise on one side and counter clockwise on the opposite side.  Being in a roadster chassis frees up many of the space constraints that are present in a full-size vehicle.
 

 

Lorena, Texas (South of Waco)

"8 to 1 headers"?

Hypothetical. i was watching video that went into induction tuning and made me curious.  wasn't sure if switching between short and long would shift the powerband or just bolster a portion of the curve. i'm looking to build a 296-318 streetcar wanting to make a quick reving engine with lumpy idle. possibly making an intake and 8 to 1 headers eventually. looking through teds articles i went with 1.5" fender header for the time being. 

Seth

Do you have a particular build in mind, or is this hypothetical?

Header tube length in tandem with tube diameter simply dictates the rpm band for that set of headers.  As the engine gets larger, so too is the need for larger tube headers.  As the cubic inches increase, the camshaft lobe profiles also need to increase accordingly.  As the engine gets larger, so too is the need to ingest more air.

Lorena, Texas (South of Waco)

While bored and unable to work on any projects i started thinking and that's where most of my problems begin. I know a lot of math is involved to actually figure out design but in theory longer intake runner length and exhaust runner length favor lower rpm power. the part i cant find is would this lower the camshafts advertised rpm range, or just make more power on the lower side or that rpm range. Ive head increaseing displacement (specifically stroke) will lower a given camshaft rpm range. 
Seth