A simple solution would be to rebuild the 87 heads and put them on the 97, that completely gets around the intake fit
Aren't the 5.7L - Vortec Combustion chamber volume 64cc ?
and the 5.7L - 87-95 TBI heads 76cc ?
You are quite correct this would resolve a major hurdle, however it would take a competent machine shop to shave the heads on an "angle-cut" to resolve the major lack of compression.
Sorry, for the lack of understanding the adapter from MPFI to TBI deal
Edit to say:
Thanks guys for the lack of lighting me up with a 55gl trash bag full of acetylene
Interpretation, thanks for not Flaming Me as a N00b here