Just thought I would write up this quick additional info for those wanting to swap to a 3.4 using the 3.4 accessories

First off is you will need to use the 3.4 oil pan, and because of that, you have to use the 3.4 timing cover, which is also necessary to use the water pump, which is necessary to do the swap, as the 2.8 lines up differently with the TC(it wont work with a 3.4 TC) doesnt have the right pulley(easily fixed i know) but also the 3.4 is reverse flow, and needs to be with the serp belt setup.

So basically, 3.4 oil pan, timing cover, and water pump are necessary, also when you buy gaskets for TC and waterpump, buy them for the 3.4, the 2.8 ones won't work. For the belt, if you delete the AC like I did, you need a 6 groove 69" serpentine belt, you CAN NOT simply ask for a 3.4 non a/c belt, the factory non a/c routing is different, if you have a 3.4 and retain the a/c simply buy the belt for a 3.4 with a/c.

Last but not least comes the alternator...if you are like me and have an older v6 using an SI alternator with a total of 3 wires, you will need to do some work here. The old setup had a junction block cable going to the post, this is the alternator's charge output, the 2 pin connector had a red wire going to this post as well, and the last wire a brown one, going into the firewall.

the 3.4 uses a cs130 alternator, and has a 1 wire connector, this needs to be spliced with the brown wire on your harness that goes into the firewall, the red wire, you can just get rid of....

So if you have to splice in lightbulb and/or resistor it goes like this:
brown wire from harness>1 resistor end>light bulb on other resistor end>grounded wire on same connection as this one.

 

As I said in another thread, it's actually '87+ that uses the oil pan that will work with the 3.4 timing cover, not just the 3.4 pan.

You could retain your alternator by swapping pulleys.

 

not quite, the brackets are different, you could use the old alt bracket as well, but using a tensioner for pulling the belt tight is better than moving the alternator around, plus have you ever tried getting an alternator pulley off without an air ratchet? easier said then done...

 

I should clarify the alternator part, while yes, you's being an '85 would require more effort, the '87+ does not, to retain the original alternator.

You should probably specify this information is for '86 and previous vehicles, instead of making it sound like it is for all 3.4 swaps in 3rd gens.

 

"Last but not least comes the alternator...if you are like me and have an older v6 using an SI alternator with a total of 3 wires"

 

*Sigh*

The number of wires does not dictate what will need to be done. IIRC there were some early serp equipped vehicles that had the 10SI alternators....

 

If the block is the same for the 2.8, 3.1 and 3.4, why do you need to use the 3.4 pan?

 

because the block itself is about the only thing that is the same, I already explained that it is a trickle down effect, you have to use a 3.4 oil pan, because you have to use a 3.4 timing cover, because you have to use a 3.4 water pump....basically the oil pan and TC have to be from the same engine as each other, they aren't independently interchangeable, but are as a group...but as six_shooter said, this stuff also depends on what year car you have..

 

To be completely correct, the 2.8 and the 3.1 share the "same" block, the 3.4 is a different block, due to the larger bores and some other differences due to additional sensors.

The oil pan difference changes in '87, and some '86s.

The older oil pan had bolts that attached the front lip to the timing cover, where as the later oil pans don't use bolts and is shaped differently.

 

So, a 1991 or 1992 3.1 like mine could take a 3.4 swap and use the 3.1 pan then? And by 'same block' I meant EXTERNALLY. Obviously the bore would be different...!

 

Yes, but honestly unless the 3.4 pan is in rough shape I see no point in doing that...

 

The reason I will be reusing the 3.1 pan, is I will be putting all the 3.1 accessories and intake back on- I live in California, so it has to pass the smog police and look like the stock 3.1 is still in place!

 

If the timing covers are the same at the bottom it does not matter which pan you use, as long as whatever timing cover you use matches the WP and accessories that you are going to use.