PPE V8 Headers GS, LS, SC
Ya not many people are posting when they get them but it shouldnt be to much longer. Have you recived your email yet for full payment?
Well i actually have been emailing PPE throughout the whole process, great communication btw and they sent me an invoice last week but said my headers wouldnt be back from coating until either friday (tomorrow) or monday and they wouldnt charge me until they were shipped out. My remaining balance for headers w/black coating is just under $500.
I just received my headers (BLACK) from PPE and they look GREAT! Looks like they have been reading the small issues we've been having as far as excess weld on o2 sensors cause mine were really clean. It's gonna be a while b4 I post my results cause I am doing a complete timing/drive train overhaul. My GS400 is completely stock now "Black on Black" but working on some mods.
Make sure you got the right headers. PPE sent me a GS430 when my car is a 400. Originally wanted polished but the black they sent me was beautiful. Much prefer black over polished, especially in CA, but they've fixed the mix up and sent me a polished set of headers
haven't put them on yet but if it helps us NA'ers, I'm sure it'll do wonders for your car. The 1.625" primaries seems to be more suitable for your application. I much rather have 1.5" primaries on a stock-ish GS.
The OEM manifold are quite possible the worst design ever if you want performance. Just when I thought the driver side was bad, the passenger side is even worse. Half the primaries don't even merge cleanly. Sharp edges everywhere
The OEM manifold are quite possible the worst design ever if you want performance. Just when I thought the driver side was bad, the passenger side is even worse. Half the primaries don't even merge cleanly. Sharp edges everywhere
haven't put them on yet but if it helps us NA'ers, I'm sure it'll do wonders for your car. The 1.625" primaries seems to be more suitable for your application. I much rather have 1.5" primaries on a stock-ish GS.
The OEM manifold are quite possible the worst design ever if you want performance. Just when I thought the driver side was bad, the passenger side is even worse. Half the primaries don't even merge cleanly. Sharp edges everywhere
The OEM manifold are quite possible the worst design ever if you want performance. Just when I thought the driver side was bad, the passenger side is even worse. Half the primaries don't even merge cleanly. Sharp edges everywhere

Regarding GS400 OEM manifolds are actually better than the GS430 manifolds. The 400s have unrestricted runners on 2 of the driver side and 1 of the passenger side primaries. The 430s have only 1 on each side. The others all enter another tube at 90 degrees (or worse like the last one of the 400 drivers side) with very sharp edges protruding into the flow. A good look will convince most that headers are a no brainer.
Here is a GS400 passenger side header. The only unrestricted primary is the long one from the front port. The second port pipe joins the first at 90 degrees with sharp inside protruding edges. This is how Lexus makes their manifolds. They cut a slightly smaller hole in the receiving pipe and weld the feed pipe OVER the hole. Not ideal for flow.
For the PPE headers, the GS430 has the O2 bung on top while the GS400's bung is on the bottom. If you try to install the GS430 headers into a Gs400, the merge collector will hit something before the manifold flange will even seat flat to the block. PPE said the headers' pipings are routed slightly different, but shouldn't really make a difference as far as performance is concerned.
For the PPE headers, the GS430 has the O2 bung on top while the GS400's bung is on the bottom. If you try to install the GS430 headers into a Gs400, the merge collector will hit something before the manifold flange will even seat flat to the block. PPE said the headers' pipings are routed slightly different, but shouldn't really make a difference as far as performance is concerned.







Cant wait for them to arrive.