look here at the most asked question

[IanSzgatti]

hi... be patient with me please! I have had the patients to search through this site for the past hour to find info on converting my 1997's 3100 to a 3100 with 3400 heads... I have to do a LIM anyways, and I'd appreciate it if somebody could provide me a link here to all relevant information which should give me a complete understanding of the materials I'd need... also whether this procedure requires any tuning of the PCM. I am a mechanic, so I wont have any troubles as long as I have the info... I dont even know why I want to do this... I guess im a car nut and I cant even leave the family car alone... oh well.

as a side, what kind of results have you other members seen out of this "hybrid" upgrade??? its one thing to have a well built/sealed motor... but if I could grab a few more ponnies out of this I'd be happy. Thank-you... i'll not ask again

[SappySE107]

Not much of a hybrid since its all gen 3 parts. The 2000+ 3100 are exactly like what you are wanting to do, minus the EGR setup (just use the newer egr, it plugs right in). 3400 heads, lower, upper, thats it. Nothing special. No special tools or program needed (but a tune would certainly help).

[IanSzgatti]

alright, so its strait forward...

but not worth it? This car is pretty gutless, compared even to my Olds 3300!

[SappySE107]

Porting the manifolds would do more before you install them, but going to a large port setup is going to be a noticeable improvement.

[IsaacHayes]

It will have the HP/TQ rating of the 2000+ 3100's. As Ben said you'll need to use the newer EGR and EGR tube if you are using 2000+ upper manifold. And you'll have to tap the LIM possibly for your coolant pipe.

[ForcedFirebird]

If you don't want them, I might just grab them because it's such a good deal , but I thought of this thread when I saw it.
http://60degreev6.com/showthread.php?t=37802

[IanSzgatti]

alvarez1112

Join Date: Nov 2005
Posts: 4

3400 Heads and lower intake!!
I have a set of '01 3400 heads that I bought new in box for a 3.4 swap but put a small block in my truck instead. Heads have never been installed on a motor. They are complete less rocker studs as they were not on the heads when I received them. $100 and buyer pays actual shipping. I also have a 3400 lower intake manifold complete with injectors and fuel rails I no longer need as well. $50 plus shipping

is this not sounding like too good a deal??? holy crap....

so you guys are telling me that with some modification these parts will bolt on to a 97 3100? im definately interested... especially in brand new heads... dang