whats needed to swap 3100 to 3400

[jairielaplante]

hello today sadly my motor seized up on my 1994 olds cutlass cruiser so I've been looking for another motor and i happen to have a 2004 chevy venture van with the 3400 and from what i can tell the blocks are basically the same except the 3400 is bored out more would i be able to take everything off my 3100 and put them on a 3400 bottom end easily without needing to change computers and such i know it run perfectly but I was wondering if this would work at all.. or is there any other easy things to do other then just find another 3100

[Pontiac6ksteawd]

If I remembering correctly, nothing is needed, you could even do a GM 3500 (not the Honda 3500 found in GM), but that does require a lot of fabrication. But a 3400 is a direct swap.

Put the engine on a engine stand, swap over everything, make sure the oil pans are the same, and go. There is only 1 difference that I can remember, and even that 1 difference is not on every engine. That difference is some engines had a 2 wire coolant temp sensor, and others had a 3 wire.

[Keiths1976]

Try and find the 2000 Pontiac grand am 3400. The upper intake is a better flow design the 3400 itself from 96-2003 are mostly identical just the upper intake is set up via van or car . Also keep in mind if you get a 2004/5 3400 it gets weird with crank position sensor the 3.5 lx9 u should have a custom tuned chip to run it correctly and also it won?t hook up to the stock ignition system in the 94 cause it needs Additional adapter to the harmonic balancer and crank sensor to run it . Plus fuel injectors would be wrong and big out over rpm . The 3400 while it?s out do the head gaskets and intake manifold gaskets while you are there . The stock heater hose off the throttle body / thermostat housing is pressed plastic fitting valve the l82 3100 that?s stock . I mean if your engine is in good shape u can swap the upper top swap heads lower intake manifold upper intake off a newer 3100 . Keep in mind the 4t60-e in your car is designed to keep the rpms lower so it don?t over rev the tranny pump and cook it . So once you swap to a 3400-3500 the Rpms revs are higher regardless the computer setting .

[Keiths1976]

Also the ac compressor is a bolt on block design so if you have working ac u will need to figure all that out since the venture 3400 compressor is different and not the bracket design the l82 has . It?s small things the block is the same mounting is the same all the fuel system will hook up ignition even flex plate are the same . I?d pull the l82 and take the timing cover off and make sure the 3400 is the same 24x sensor behind the harmonic balancer the bolt holes are there . If not you have to change that over to . Select 3400 are different sensor wise if you go to new . But if you have the 3400 out change the timing cover gasket and check the timing chain while u have it out .