Not for my locost this - just collecting the general vibe on the exhaust in my V8 mazda mx5. Tight squeeze to get the exhaust in, the system pairs 1&5 2&4 3&7 and 6&8 then takes these 4 pipes to a silencer at the back. The paired cylinders are firing on a 5/3 beat (close as I could get to 4/4). On a dyno power run the rear exhausts got noticeably hotter than the others but I've a feeling this may be a distribution issue with the bobbins offenhauser dual plane iinlet manifold + fuelling marginally weak at WOT (can't remember if it was 12:1 or 13:1, think it was 12) Has anyone else made a V8 exhaust this way? Engine's a 4.6 rover torque ~230ft lbs power 212 @ 4krpm.
BTW - Lots of smoke on the dyno - seems I need a glop catcher in the breather line...
Cheers
Bob

Sound all wrong chap , You shouldn't be pairing anything up at all!

Keep left/right bank seperate or fit a connecting pipe on secondaries!

P.s. there's nothing wrong with your inlet manifold.

Rgds

Roger www.shinybitz.co.uk