I have a question I have a 2007 trailblazer with a low end knock the head is in good condition would it be possible to use the bottom end from a 2003-2005 onto my 2007 cylinder head in my 2007 trailblazer. If so what else would I need to change
2007 Trailblazer 4.2 Cylinder Head Swap On 2003-2005 Block
- Thread starter Shadohc39
- Start date
Mooseman
Moderator
AFAIK, it's a straight swap. You'll of course you'll reuse the valve cover and coils from the '07, which will make the hook up easier to your 07 wiring.
Be forewarned that head re and re on these is one of the worst jobs. Need special tools for the timing chain retention and the broken head bolts that WILL happen.
Engine swaps are also more complicated on these because of the diff on the pan, unless it's a 2wd.
Be forewarned that head re and re on these is one of the worst jobs. Need special tools for the timing chain retention and the broken head bolts that WILL happen.
Engine swaps are also more complicated on these because of the diff on the pan, unless it's a 2wd.
Mooseman thanks for your response I am just trying to do this the most cost efficient way since I have both engines and know what the other ones needs
Heads up:
If the donor head is missing the VVT Sprocket; you'll need the VVT Sprocket for that year head. The P/N and design changed slightly several times over the years on the Atlas LL8. Discovered this when researching a later year head swap, for a future Turbo build.
If the donor head is missing the VVT Sprocket; you'll need the VVT Sprocket for that year head. The P/N and design changed slightly several times over the years on the Atlas LL8. Discovered this when researching a later year head swap, for a future Turbo build.
I have two complete long blocks one is from a 2003-2005 and I also have a complete 2007 trailblazer
The donor head that I have is complete
The donor head that I have is complete
Last edited:
limequat
Member
- Dec 8, 2011
- 520
Should be no problem. I haven't heard of anyone completing this swap, but it should be the best of both worlds. Higher airflow from the 2007 head and (rumoured) better crank from the 2002-2005.
I have had customers run 2006-2007 electronics on 2002-2005 engines, so I know electronics will not be a problem. You will need a CASE relearn when you're done though.
I have had customers run 2006-2007 electronics on 2002-2005 engines, so I know electronics will not be a problem. You will need a CASE relearn when you're done though.