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Location: >Articles>Swapping a 3500 upper onto a 3400 engine

Swapping a 3500 upper onto a 3400 engine

The 3500 upper intake is great for the larger plenum volume and stock 65mm TB opening, but presents some issues when used on a 3400 lower intake.  This is a work in progress article though anything not pictured and fully explained will at least be mentioned.

Stock fuel pressure regulator and bracket interfere with the fitment of the 3500 upper intake.
Here you can see how far off the manifold is from bolting to the lower.
The first step is to loosen the 2 bolts holding the lower. They won't be like these but you can see the location. Loosen them only, as you will want them in place for the next step.

Missing a picture, the TCE FPR bracket is necessary to clear the 3500 upper intake, but are being redesigned right now.

Grab the fuel rail and pull it towards you so the regulator is moved away from where the 3500 upper throttle body arm would be.

I know, this looks like the picture above, but check the distance between the bracket and the "00" to see how much it moved. Tighten the 2 bolts while you hold it in this position.
The 3500 upper intake uses a different MAP sensor setup than the 3400.
The easiest option is to have this tapped and plugged.
Or you can run an adapter pigtail and get the MAP used for a 3500 (and other newer engines)
The 3500 is missing some vacuum ports compared to the 3400. The 3500 CCP (charcoal cannister purge) location is excellent for tapping a new 1/4 vacuum line to be used for the FPR and 3400 CCP setup.

 

And now for the parts that aren't pictured.  The 3400 CCP  will no longer have a place to bolt down to, unless you find a mid 90s grand am or equivalent with the 3100 and take the CCP bracket off it.  These were mounted onto the same bolts as the ignition coils.  It will not hurt anything to let it hang off of the vacuum line however.  Also, the 3500 upper changes the ignition coil bracket bolt locations.  You can either bolt the bracket to the studs on the rear head, or the manifold itself.  The throttle body will require the TCE Throttle Body adapter, and is recommended for use with a TCE Billet 62 or 65mm Throttle Body.  The original 2000+ 3400 EGR needs to be swapped as the 3500 EGR is slightly different on its EGR tube to manifold setup.