Just for giggles I poked ebay to see how much an earlier 4200 was going for - this a long block engine - $375.

http://www.ebay.com/itm/03-04-TRAILBLAZER-ENGINE-4-2L-VIN-S-8TH-DIGIT-464196-/141997558969?fits=Model%3ATrailblazer&hash=item210fb6ccb9:g:aCwAAOSwmc1XPPUr&vxp=mtr

51 GMC 4.2 turbo
Can't solved today's problems using the same technology/thinking that created them