aklackner wrote: ↑Tue Feb 16, 2021 9:01 amI’ve personally attempted to bolt an LS manifold to a b18C5, it wouldn’t clear the ITR transbrace. The LS has 2 smaller L brackets that provide better clearance. The issue was in the radius where it starts to turn to come under. The LS one made 2 bends to taper close to the motor.PaulMc wrote:Well, part number for the ITR downpipe which the ITR cat would bolt to is 18210-ST7-R62. That part number shows compatibility with the 97 LS and 98 GS.
https://www.acurapartsforless.com/oem-p ... wtbDQtZ2Fz
I’ve not had hands on a USDM lower manifold but the 96 JDM cast manifold came straighter down and had a tighter bend down low to provide more clearance. With the significant ITR transbrace it makes sense that it would have to be arranged differently to clear where the LS manifold the secondary runners sat next to each other flat under the oil pan this doesn’t really account for why the flange would be clocked differently, and if the parts catalog shows compatibility that might be why bolt in support is limited?
I don't see anyone debating here.
I'm not sure why the catalog would show compatibility but you could be right about the reason why. I never tried to use the LS downpipe and never had the USDM next to one to compare. I have a CDM one on hand, and I'm curious the difference between the JDM 96 spec, CDM and USDM downpipes, exactly.