1.6 to 1.8 fuel rail compatibility
 

I have a OBX Racing billet fuel rail on my 1.6 NB (JDM 1999); I will be building a 1999 BP4W engine in future, and am wondering if the rail will fit the BP4W? The question arises because I assumed the wider bore spacing on the 1.8's would have a different rail,(wider injector spacing), but I see OBX lists the rail for 1990-93 1.6, and 94-97 1.8. They don't list it for anything newer, leading me to think the BP4W head has something different in mounting, etc. Anyone gone down this road who can share some incite? Or recommend a billet rail for the BP4W that makes for easy AN hardware, (that I already have).

1.6 rail wont fit on a 1.8.

99+ heads have higher intake ports than earlier bp heads, so earlier oem bp rails wont "fit"

FM still sells a rail that fits both 94-97 and 99+. (dual mounting holes for fitment on either head) Thats what I have. https://www.flyinmiata.com/fm-fuel-rail-only.html

Radium does too that also fits both Fuel Rail, Mazda MX-5 (Miata)

Thanks, just the info I needed!