3400 vs. 3500 vs. 3400/3500 hybrid?

[Corey]

Hello everyone I just wanted to run this by you and get your opinions. I have a 1995 Pontiac Grand Am with the 3100 with 173,000 miles and I am getting ready to do the 3400 swap ,but after looking in the forums on this site I see that their are lots of different combinations like 3400's with a 3500 top end or a 3400 with a 3500 crank. So I guess in a nutshell I'm just trying get the most bang for my buck any suggestions?

Thank you, Corey

[rickykline]

3400 with 3500 heads and lower intake would be the easiest and most affordable...

[PCGUY112887]

3400 with 3500 heads and lower intake would be the easiest and most affordable...

I woulden't say that, 3500 heads is going to cost you. I'm not sure about the lower.

Plus then you have to stick with the special 3500 gaskets and drill your block, no big deal aside from the fact that you have to get GM's gaskets and those are $$ too.

[gectek]

what do you have to drill out on the 3400 block to make the 3500 heads fit? and also does anyone know the CR on the 3500head 3400block hybrid?

[Young Whitey]

What do you have to drill just the alignment holes for the lim gasket?

[PCGUY112887]

With the 3500, you don't use RTV sealent crap between the 2 heads on the block (on the very outside edges), the 3500 has this gasket that goes there. However you have to drill some holes in the block so the gasket's little feet things will stay, then you can put the LIM on.

There is a pic somewhere, from v6ho I think.

[rickykline]

you dont have to drill the holes for the gaskets you can just cut the tabs off... i did.. gaskets are cheap at employee cost.. lol

[rickykline]

i did a price write up on everything.. ill find it lower intake manifold cost me 136.10 NEW

[rickykline]

let me make a list of what is needed to do this swap...

1. 3500 heads
2. 3500 lower intake manifold
3. 1/2npt tap for coolant nipple
4. new lower intake manifold gaskets(you must use the orange strips and cut off the little tabs that are supposed to push into the block)
5. new exhaust manifold gaskets
6. 16 new head bolts
7. red loctite
8. 3400 head gaskets
9. upper intake manifold gaskets
10. drill bit and tap for ect sensor(will post sizes tomorrow)
11. 3500 rockers
12. new valve seals
13. new injector orings
14. new thermostat gasket
15. water pump bypass tube oring
16. and lots of torque specs...

if i think of anything ive missed ill edit this post

[PCGUY112887]

ECT sensor... isn't there 2 of them? (on older styles that is) 1 near the tstat, and 1 somewhere else in the head? I just thought I remember from people talking about the 00+ 3400 head swap that you could swap out the other ECT sensor for a 3 wire one, and wire the wire that went to the ECT in the block to the other one? Or am I just crazy?

[3.1POWER]

A little off topic, but can i put 3500 heads and manifolds on a 3100 block>? Id assume one could. Or would the 3400 heads be better for a turbo setup??

[rickykline]

the 3500 lower intake manifold doesnt have a ect in it so i tapped it for one so i didnt have to extend the harness... so i plugged the head port..

[onefastV6]

I drilled the block for the 3500 LIM gaskets. It only took approx 15 mins and it will keep the gaskets secure and aligned.

As for the ECT sensor, I opted to extend the sensor rather than mess around with tapping the 3500 LIM. It only needed to be extended approx 6". Just make sure that you solder and shrink tube the connections.

You can get a whole 3500 top end gasket set from GM for $140 shipped from GMpartsdirect. Part #12594816

Pics of the gasket set can be see here: http://60degreev6.com/showpost.php?p...4&postcount=18

[rickykline]

i listed all i needed to get it done.. and since i picked up the heads for 200 i did the entire swap for less than 450

[blackbombshell95]

Corey? You stole my name