Or at least 3/4 of it does. It looks like the old Vortec 4.3 has survived the cut in the new 2007 pickups. Since speculation of the death of the midsize SUVs (GMT360 if I remember right) is rife, does that mean the end of the line for the 4200 I-6?

Seems a shame if that's the case.

I'd love to see that engine with a turbo!

 

The 4200 I-6 (and it's cousin, the 3500 I-5) are being replace by the new 4.5L I-6 and 3.7L I-5.

 

I knew about the I5, but not the 4.5 I6. That's good news, and I hope it means the engine's staying around for a while. Now all it needs is a more exciting home than the Trailblazer (and I don't mean 9-7X!).

It'd be great to see a new gen Syclone and Typhoon with a turbo 4.5 I6.

I wonder if a short-stroke version of that engine would fit in the RWD cars (it looks a bit tall as is)?

 

They could still make the 4.3 a performer if they would give it better heads, direct injection, and better intake design. Not that it's bad. But jesus, it's been at 200hp forever.

The shortblock is bulletproof. I have no problems with the 4.3L engine, just the fact the technology hasn't been updated on the top-end.

 

It would be nice to see the 4.3 get the LSx treatment, aluminum block, the whole works. That should give it 260 - 280hp range, and if its based off of the LS2, then displacement would go up some too.

 

21st century truck.....20th century engine. This makes me sad. I was beleiveing the 4.2LI6 would go in. Imagine the bragging rights. Ford and Dodges V6's are far newer.

When they are building a world class truck, burdening it with a old, dirt cheap engine, seems rather, well, cheap to me.

 

I'm still surprised they went to an "I" motor instead of a v6 version of the LS1. "I" motors make a lot of torque, but man, they take up so much room and they're heavy.

 

I dunno about an I5 (my bro's colorado has balance shafts), but an I6 is a very smooth running engine.

 

werd, the old style small block needs to stay dead and buried. The LSx engines are so far superior, I cannot fathom (other than readily available and cheaply modified - although the returns per dollar spent seem to pale against the LSx engines) why people still bother to mess with the previous gen SBCs

 

Even the 242HP 3.7L I5 would be a big improvement over the old 4.3L.

291HP 4.2L I6 vs. 195HP 4.3L , that choice should have been a no brainer. The Atlas I6 has been out since 2002 MY.

 

maybe the 4.2L isn't as fuel efficient as the 4.3L

probably just a cost saver. they still like to advertise a NEW fullsize truck for 10,999 or 11,999 at the local dealerships.

 

GM did have an LS1 based V6 similar to the 4.3 but it never made production. the 4.3 puts out 260 lbs/Tq, more than the I5. and the 4.3 is a very old motor. If they gave it the LS treament it would be far superior to the I5 IMO. Plus it would make more torque and take up less vertical space then the I6.

 

If you chopped 2 cyl's off the 310hp 5.3 you would have a 232hp and 251tq 4L. Not too bad, but really not much more impressive than the 4.3 and 3.7 I-5.
I've driven plenty of 4.3 W/T silverados and they have all the power you really need, and they get pretty good mileage too 20+ highway.

Now if you had 3/4's of the new 6.0 with 367hp it would be a much more impressive 275hp 4.5L V6

 

The V6 is fine for normal acceleration - sucks at WOT, though.