I think i'd look for a bone yard find, with less miles on it, the S10 & Sonoma's should be the same engine you may have to use your top end sheet metal from your engine. They are available around here warenteed for $500.00 to $800.00. but yep it's got to come out the bottom, probably a day to a day and a half work, if you have a warm place to work.
JMO
Zip.