Call Eric @ GBODYPARTS
Call Eirc @ GBODYPARTS (252) 825-3293 , They may have a oem used one that has never been touched for you to port.
I ported a couple for my hot air turbo Rivieras , it used the same intake, I also had IWIN engineering do one , They port matched the intake gasket to the manifold,you know the intake is also the valley pan, a one piece unit.
I , myself worked on hollowing out the runners with long flexible shaft attached to a just right size worn down sandpaper flap wheel on an electric drill.
I also modifed that BLUNT flat divider where the turbo adapter sets, you know , the air inlet to the intake divides into 2 folded runners, LEAVE THEM ALONE LIKE THEY ARE, KEEP THE OEM DESIGN, just enlarge ,
TAKE OUT ALL THE CASTING PLUGS UNDER THE INTAKE TO GET A GOOD LOOK AT THINGS, THEY ARE SQUARE DRIVE PIPE PLUGS, I replaced mine with EARLS aluminum pipe plugs that are hex drive.
THE long runner design is good for low end torque, when you carve out some material, you will be changing the total cubic inch displacement of the intake and will be like having a larger plenum. NOT much but it adds up.
THIS information is what I did, and many may disagree, a lot of people want the the hot air intake to act like the 86-87 design and hack it up and repipe everything and add a intercooler with miles of piping.
Keep you hot air , HOT AIR and cool the charge with propane or alky injection.
MY TWO CENTS
GOOD LUCK, TURBO E38