I’ve been working on some itbs for the RB for the last month or 2, using a cut down RB25 inlet manifold.
Tig welded on some extensions to match the RB26 throttle bodies then welded a 10mm plate on to bolt the tbs to.
Made up the linkage support from 10mm plate.
Then cut out some thinner plates, cut some bent alloy tubes and purchased the trumpet tips. My welding isn’t neat enough to finish the trumpets so I’ll have to pay a pro.
Should be on and retuned in a few weeks.