That will depend. Your looking at about $500 in parts, about $200 in gaskets, plus the tune. You may also need to upgrade your transmission if you have a 4t65e. Upgrading that to a 4t65e-hd is easy, just change the output shaft, diff, and diff cover. Perhaps $100. The tune will be the problem. If you have your own software, $500 you can do it yourself, but the learning curve is a bit steep.
If you can find a good L67 engine, you will need to also get the wiring harness and PCM. Swap that all out and your set.
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1997,1998,2000,2005 year confused Bonneville SSExi. Stock? ish.
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