HI Mike, yes the bird RA system very complex & hard to find. The upper pan is same for RAIII & IV, but the bird slightly differs from TA. The lower /RAIII/RAIV pans are the same. There is no lower now made in steel, but I've seen a RAIII modified to a RAIV. No one does the raiv exh. manifold shield.
There are no more repros being stamped out, so now even the copies are hard to get. I'm having the RAIV exh. manifold shroud done exactly if anyone needs one. I'm pretty lucky my TA had all orig. RAIV parts, & I have all parts for my raiv convert.
