3400 year changes

[JohnnyReb]

Are there any major changes to the 3400 from a 1998 to 2004. I have found that some changes were made to the heads, mainly rocker mounting bolts, any other head changes? I know the upper intake is different, what about the lower? I have also read of some cam and cam sensor changes. If they affect these years will the cam/sensor interchange? I have also found information concerning crank changes, something about the sensor in the side of the oil pan and notches in the crank but I have not been able to find specific information on years. I changed a tranny for a friend. He had a 98 venture and brought over a wrecked venture. I dropped the subframes and changed the tranny and got the leftover parts for my effort. The wrecked donor had 31k. I have a 04 Montana and was hoping to keep the 3.4 for future use. If it won't work I have no reason to store it. Any help would be greatly appreciated.

[SappySE107]

The cam sensor and cam trigger aren't a problem. You could drop the 98 motor in and use the 04 upper intake and fuel rail (injectors changed, fuel pressure increased in 2000). Crank is the same, etc. If it ever comes to this, pull the lower and install the metal felpro intake manifold gaskets as well. Get a high temp brown o ring for the oil pump drive as well. Then it should be solid (your 04 might have the metal gaskets, but I don't know if GM switched it or not). Oh damn, and the lower is probably threaded for the coolant line vs the press in fitting. You would have to check and see since I don't know what the minivans got.

[JohnnyReb]

Just got back in from tearing it down. Rotating assembly still in block but all else gone. No engine is a candidate for a swap without a proper check. I'll plastigauge it tomorrow. Before I pulled the subframe I tried to start the engine, wouldn't start but I didn't go beyond a fuel pressure check. I know the van was running, it got t boned in the side. Went to pull the cam and got 1/2 of one so far. I read in this group about the hollow cam but this is a 1st for me. My main concern for a swap would be the long block assembly. I would never go through any engine swap without a complete gasket job, especially one that has sat for years. So if all of the long block is the same I'll check clearances, obviously install cam bearings and cam then prep it for storage.

Next the cam, obviously one must be bought. The cam trigger and cam, by the previous answer I am still lost. Are they the same or just interchangeable. I see that the store sells a conventional style solid cam for 94-99, would the 94-99 trigger work with the 04 PCM? Or would the 04 trigger work with the 94-99 cam? Hate to drop 175.00 on a cam for nothing.

[bszopi]

They are interchangeable. The trigger works by sensing either a rising edge or falling edge (can't remember which one), but with all 3 different cam trigger designs, the edge is in the same spot, so the sensor still picks up the proper signal. All signal conversion is done inside the sensor, so it sends the correct squarewave out to the PCM.

[19Cutlass94]

The 2004 can be used with the metal felpro gaskets. Thats what Im using right now

As for the sensors, the crank sensor in the side of the block is the same thing as what youve already got, infact, its the same sensor in my 3100, so dont worry about chaning it.

Besides for the different design of the sensors, the only other difference I could tell where the UIM, the 8mm rocker studs, instead of the 10mm. And i believe depending on the application of the engine, you could have either pressed in or threaded coolant pipe, but more than likely its going to be pressed in.