For $1200 you could do a 4200 swap and have a 275/290 HP engine with no mods to it.

Keep the existing iron 6 for a later restoration/return to stock.

Best method is to get a rolled trailblazer/envoy and pull the the parts yourself.

If you want more power - turbo it == 400/450hp easy.


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