I had a long talk with the PO last night and learned the following:
the 1.25" SU was chosen specifically to hold the boost down under 15 lbs,
and he advises to keep it below 10lbs. since the 1.25 easily allows this
level of boost, more air is not necessary. He said that he had done
some smoothing of the combustion chambers, and carefully matched their
volumes. He said he welded the intake/exhaust manifold out of black
water pipe ground and fitted, arc-welded and painted. the faceplate
was cut from sheet steel, cut and ground to fit.
I found a place in Texas that deals with turbos and found that RAYJAY
was bought out and although the same turbo is still produced, it has
become prohibitively expensive and they would suggest several others
that are much more affordable.
Regards, Glen Byrns