3500 swap insted of 3400?

[96gaGT]

Would a 3500 swap in a 1996 grand am as easly as a 3400?

I was planing on swaping my 3100 for a 3400 with the 3500 top end but if i had the choice id like to just use the whole 3500.

I know theres not alot of after market parts for the 3500 right now, but im sure within a year this will be the beast to have.

[bszopi]

No, it is not as easy. There are several addition (and somewhat expensive) pieces that are required for the 3500 to work in an older car. You need a new, external timing trigger for example (there is one available in the 60V6 store) because the crank trigger went from a 7x to a 56x (?), therefore it is incompatible with the older PCMs.

[96gaGT]

Is there a guide you can point me to that lists all the peaces that require modification ? and besides the pcm problems will it bolt in on the stock mounts?
Becouse if it dosnt even bolt in the stock mounts then im just gunna stick to the 3400/3500 idea.

[IsaacHayes]

Then again, it may be cheaper to just swap the whole 3500 and buy the external adapter since if you are buying a 3400, then 3500 heads/intakes, and then gaskets too, that cost will add up fast!! Heck just gaskets alone probably is the cost of the adapter. So if you could do a whole 3500 you just got the price of the engine and then adapter... Plus all the other benefits such as oil squirters, etc and the nice exhaust manifolds which would be good to adapt to work with your car rather than reuse your 3100 setup since the 3500 manifolds flow so much better.

IIRC it should bolt up in a 3100 equiped car. I know someone has one in a beretta, and the crank trigger adapter fits! Don't know about an N body but I would suspect it would too. You'd likely have to use the A/C compressor on the 3500 since I think it changed mounting style/bolts, don't know for sure though. You have a 96 ODBII so you have the stepper style EGR, so you could use the 3500 EGR it will connect to your wiring harness. You'll need it's EGR tube too regardless of if you use the 3100 exhaust manifolds or 3500 manifolds. You'll probably have to tap the LIM for your threaded coolant pipe (same with any 2000+ 3x00).

You'll re-use your fuel rail/injectors. You will have to grind on the plenum TB neck a little to clearance for the FPR, or take it off, hand bend the fuel line tube then put the FPR back on.

I think the only real issues over a 3400 swap is the crank trigger, and course the 3500 plenum stuff which you'd run into anyways if using the top end on a 3400. (splice in the new style MAP, get the TB adapter, tap the hole by the EGR for a NPT 1/4" is it? and put a nipple in there for vacuum source and T it off for the FPR and transmission). If you search under my name for 3500 you'll find my thread that had a lot of info on swapping the 3500 plenum over that will help with that aspect.

I would look at the pics here and see if your N body mounts the same way.
If it does then the external crank trigger should fit. Check out the pics of the trigger mounted. (btw, this is news to me, I didn't think it'd fit an L body but I guess it does!)

Personally I think it's worth the time/effort to just do a whole 3500. Low mileage, complete new engine. Actually time and effort might even be less since you aren't swapping heads/etc. And cost could be less too even with the adapter depending on how cheap you get your engine(s).

[IsaacHayes]

I found this pic http://www.domesticcrew.com/chris/ca...a/IMG_2121.jpg that shows that it looks like the adpater needs to be modified to fit an L body. The bottom bolt hole "leg" needs to be ground shorter the amount of the body mounting bracket so that it sits right. I don't know if a grand am has the same mount on the block or not right there.

[96gaGT]

I think im gunna look into getting my hands on a 3500...

Lets see With the motor ill need AC, EGR/w tube and a after market crank trigger. Now about the plenum... is their any after market ones that would save me the trubble?

[IsaacHayes]

Not sure with the AC. You may be able to adapt the 3500 ac compressor or put on a 2000+ 3400 ac I have no clue. But it's something to look into. Maybe someone knows the details?

You can bolt up a 3400 UIM in place of the 3500 plenum to save you some time and get the swap running faster. Then everything will bolt up and connect like normal. Go with a 2000+ 3400 plenum or 2000+ 3100 plenum and you can use the 3500 EGR/etc. That way you can get it all going, and later on when you are ready put back on the 3500 plenum (it's a better design and makes more power) you don't have to worry about the egr, as all 2000+ 3x00 manifolds share the same EGR.

You will have to use the 3500 lower intake as it's the only one that works with the heads. You'll likely have to tap it for the coolant port area as I think yours is threaded since it's a 96 and takes that threaded fitting.

But yeah a 3400 UIM will bolt to a 3500 LIM just fine and works with everything you already have without tweaking anything.

EDIT: You can re-use your exhaust manifolds (I think, might want to confirm the bolt pattern will bolt up) as its less work, but if you could use the 3500 manifolds that would be the best since they flow really well over the 3100/3400 logs and are like shorty headers basically. (and dual exhaust as the front goes under the oil pan as it has a notch).

[96gaGT]

I plan on trying to get a whole 3500 from a junk yard so i guess ill grab the manifolds, plenum... and AC just to be on the safe side. but should i take the EGR too? will the 3500 manifolds work with my 96 EGR?