02 3400 top end onto 95 3100??

[spankiniroc]

Hi guys, new guy here but been on v6z24 for a while. i just got the top end that g-u-not was selling and I was wondering would there be any complications bolting the 02 top end onto the 95 3100? I know I'll need to get new exhaust manifolds and a 4 wire O2 sensor. Do I need custom pushrods or can I just use the ones I got with the top end? Also, one other question would there be any difference between bolting the 02 top end onto a 3.1 or the 3100? Pro's or con's between the two? The reason I ask is I have the 3100 in the car and I have a 3.1 sitting in my garage.

thanks
Jason

[bszopi]

Bolting the 02 3400 top end onto a 95 3100 is almost a direct swap. You already have a 4-wire O2 sensor stock, so that is not an issue. Your exhaust manifolds will bolt up to the 3400 heads, so that also isn't an issue. Things that will be an issue is the EGR (will need an adapter) and the heater coolant hose (yours is a screw in, the 02 is a press-in). Neither of these are that big of an issue though. And as far as the pushrods go, they are the same length between the 2 engines, so either will work. Just make sure they go in the proper position.

[3100 MPFI]

when you say top end swap, are you talking just upper and lower intake manifolds, or heads and everything?

If you are doing just the intake manifolds, there is some minor clearance issues with the stamped steel rockers. Other than that, the 3400 lower and upper intake manifolds are a direct swap (other than the coolant lines which are only a minor thing).

To do it to a 3.1 MPFI would require swapping the heads as well.

Oxygen sensor does not matter. The 1 wire sensor will fit where the 4 wire sensor goes. I ran my 1988 Cutlass Surpeme with the newer top ends, and the newer exhaust manifolds, but kept the 1 wire sensor (1995 will have the 4 wire already).

[bszopi]

I assumed heads also, since he stated he bought G-U-NOT's setup, which included the heads.

[spankiniroc]

Yes, I meant the heads too. No, I don't have a 4 wire O2 sensor it came with a one wire sensor. Are the exhaust manifold ports big enough to match up to the larger heads?

[bszopi]

I guess I'm confused then... Or maybe, since you have been a member of v6z24 for awhile, you just have a 3100 swapped into an older j-body? Then the single wire O2 would make sense. So then the question becomes, which exhaust manifolds are you running? There hasn't been a change in exhaust port size ever for the 3100/3400 heads.

[IsaacHayes]

Yeah what car are you running? V6z24.com has a write up for installing a 4wire heated O2.

The exhaust manifolds from any 3x00 will bolt up, but I think the impala 2005 or something ones are a bit larger inside for more flow.

[spankiniroc]

Sorry, I was thinking that since the 3400 had larger ports that they would need different manifolds. Didn't know they were the same. I'm using the manifolds that came with the 3100. As for the O2 sensor, I got the 3100 out of a 95 lumina, and it had the one wire O2 sensor and the same egr valve as the Z-24's stock one. The car I have is an 89 Z-24 with the 95 3100 and I swapped in the 5spd. Sorry I'm just trying to make sense of it all and learn what's what, Didn't mean to confuse anyone.

[IsaacHayes]

You'll want to use the 3400's intake manifolds but exhaust manifolds you can use the 3100.

95 lumina had single wire O2? That must be someone's handy work there... should of been 4 wire.

[ecko614]

what kinds of benefits do you get from doing somthing like that?? im a new member here and been on grandamgt.com and gaownersclub.com for a lil while. Anyway i just purchased a 1995 Grand Am GT for $500 about 6months ago. Decent lil motor (3100 V6)but ive heard alot about people doin this 3400 top end swap. I was really intrested in this swap and wanted to know of-if any....pros and cons of this swap. Thank you to all who can answer. Would it be more effective to do the 3500 top end swap???

[3100 MPFI]

since it is a 3100, you will need to do the 3400 top end swap. The 3500 heads will not clear the combustion chamber.

You can do a 3400 top end swap, but use a 3500 upper intake manifold. If you go that route, you will need a throttle body adapter seeing that the 3500 uses drive by wire, and the older cars don't (different bolt pattern). Everything else is pretty much the same, as far as fitment goes, but you will need to do some grinding for the fuel pressure regulator, or something like that. The people that have done the swap will know for a fact. It is still on my TO DO list.

There is only PROS from doing the 3400 top end swap. It will give you a chance to do some repairs to know weaknesses to the 3100 (lower intake manifold gaskets), and you will gain power. The 3400 and newer 3100 has larger intake manifold ports, so you get more air.

If you do this work, my only other piece of advice is that if you don't get headers, then at least have a custom exhaust downpipe made that is a larger diameter. The stock one is as small as 1 7/8's in some cars.

[IsaacHayes]

Headers won't fit the older grand ams... Same problem like us J and L bodies.

[3100 MPFI]

yeah, and us W-bodies. I had them headers on my 1988 Cutlass Supreme for a while, but I finally took them off when they cracked. I never got around to putting in a flex joint.

[Barry]

I have a big port Uim and Lim for sale. Current offer is 75 shipped in the usa. If you can beat that, there yours.