yet another 2.8l/3.4l swap question

[Jaxom]

What would you do in my situation. And that is. As I've mentioned in a previous post or two, my '88 s-10 with a 2.8l has a dying tranny. That's the older 700R4. After reading about the 3.4L swap I thought I might want to give that whirl. But I need the trans done now, in order to job hunt. This would mean changing trannys again once I swapped out the 3.4L because I would need to use a 4l60e tranny.

Fortunilly I was just reading another swap thead, and Raven made the comment that one could just swap upper manifolds, efi and tbi onto the 3.4L. This would mean I wouldn't nessarily need to upgrade to the 4l60e which is good news.

Now my quandry is this. As Neo points out, if you install a HT into a vehicle not listed by gm, or modify it in anyway, you void the warrenty. Yikes! That's an awefully big risk after shelling out $1500-$1800 for a new engine. There very well could be something wrong with it, and I'd be sol the moment I take the new manifold off.

On the flip side of the coin, being that I live in a major metro area, I can find used 3.4L's all day long. The only drawback being that I've never rebuilt an engine myself before, and I'm not sure I have the skill set to do so. Paying a shop to do so, eh, that can get expensive as well.

Of concern...I was reading through GM's online catalog, the HT 3.4L is being discontinued, so getting one of those may not be that easy in the future. That means the camero/firebird 3.4L's will dry up after that. What would you do in my shoes?

Thanks,

Jax

[neo71665]

Rebuilding motors is not that hard but requires some specialized tools that no offense I doubt you may have. You might be better off letting a shop do it or maybe try to see if there is a local class being given on it. I wish I could say sure jump in on it but I know you have mentioned in the past money is tight and I doubt you wanna buy a few hundred dollars worth of tools before you even start. So far the engine alone I have about $600 tied up in my rebuild and still gotta get some more little bits here and there. After everything is said and done I figured my rebuilt engine gonna run about $800. I went this route cause I ported a set of heads and knew what cam i wanted, and wanted roller rockers. All of which woulda ruining the warranty (not counting its going in a 87). If you install the crate engine yourself you might be able to fool the system if you tell them its going in an older truck but if any warranty work comes up pulling the engine to take to them might be a pain and they might not like it.

I just kinda lucked out (or a curse depends on you look at it) and was born to a father thats a mechanic, grandfather was one, and uncle that works at a chevy stealership.

[Jaxom]

True, true, buying $500 in tools would be just and added expence. But...and this is a big but, I could always get those tools from Harbor Frieght for one time shot, so to say.

Another thing I was thinking aobut is this. Having a shop do the short block assembly for me. I'm most hesitant about doing the lower end anyways. And that's were alot of those specialty tools would be used.

Oh, there was another question I ment to ask before as well. In order to swap tanny's, the Y pipe needs to come out. My entire exhaust system is pretty much shot, I'll like to put headers in at this time, but I think I read something about the exhaust manifolds are different, one being "D" shaped, and the other not, is this true?

And this leades to yet another question...(sheesh!) The transfer case has to be dropped as well. Both Haynes and Childens mention this has to be drained, and then refiled after it's re-installed. But the don't show how or where to do this. Since I'm replacing the shot trans, should I think about having the transfer case rebuilt too at the same time?

Sorry about the questions, I was really getting fed up with the truck and was concidering dumping it. But the radiator went, and a buddy loaned me the $ for a new one. (Things are getting better cash wise so I'm paying him a few dollars a week for this). But since I now have a new radiator, will have a new trans, and a new power steering pump, and a new condensor, and bunch of new sensors, I might as well keep the beast now.

Jax

[The_Raven]

I don't know why you still have this idea that you need to use a 4L60E with the 3.4, you don't. A 700R4 will work just as well behind the 3.4, since the 700R4 and 4L60E are essetially the same tranny, just the 4L60E is controlled via a PCM, where as the 700R4 is mechanical, except for the TCC, which only controls converter lock up anyway and the trans will shift fine without the TCC wire being connected.
Another issue with going to the 4L60E would be the lack of mechanical speedo output, it can be added, but is not easy. I'll be doing this in my Grandfather's '71 Chev truck, once we get the EFI up and running.

As mentioned in many threads, you could retain your current EFI, which you would need to do with the crate 3.4 anyway, since it doesn't come with an intake manifold of any sort anyway.

Rebuilding an engine is not hard, and honestly, the bottom end is the easiest part to rebuild and requires not much more than basic hand tools, at least for tear down and re-assembly. Let the machine shop do the cleaning and machining, and installing the new cam bearings, then re-asemble it yourself. Just need an assortment of sockets, extensions and ratchet, along with a quality torque wrench. A ring compressor, which can be bought cheap, especially when you only plan to use it for a single rebuild, is about the only other "speciallity" tool needed, for re-assembly.
You could buy a cam installation tool as well, which is basically a handle that attaches to the cam to make sliding the cam in the last few inches very easy, compared to not having it. Another tool that can be useful is a ring gapping tool. You can buy one or do as I did and make one from a grinder disc, a piece of C channel, some threaded rod and some nuts that fit the threaded rod, to set the ring gap. So you'll also need a small feeler gauge set, but this can be used for other things as well.

Ring alignment, cam, main bearing installation and other techniques and things to watch out for can be found in an egine rebuild manual. There are some things to watch out for, but as long as you pay attention to a rebuild manual, you'll be golden.

Something else to keep in mind is that once you buy these tools, you'll have them, and many can be used for other things, like the torque wrench can be used for many other projects.

All RWD 660s use the same exhaust ports, it is only the gen3 FWD heads that went to the D-shaped ports. SO any header that will fit on the 2.8 will also fit on the FWD 3.4.

[Jaxom]

Raven, about the tranny's. I would WANT a 4l60e behind a 3.4L...if I did a hybred swap. But as you pointed out in another thread, if I stick with the same upper, efi and tbi, I can stick with the 700R4. It's not a matter of "must" use, rather a choice, of, if you're going to go as far as doing the hybred, even with my newbie opionion, wouldn't it be wise to use the proper trans matched up to it?

And yes, I've read, you can trick the ecm to thinking it has a 4l60e when it actually has a 700r4. But that goes back to skills and just how much I wanna rig.

I need to get to local bone yard in the next week or so for a tailgate, while there, I'm gonna ask about engines. Before I buy one, is there a book...other then haynes/childens that detail a rebuild on the 660's? Something written for us dumb newbies?

[The_Raven]

*sigh*

There is no "proper" tranny to put behind a 3.4 hybrid or otherwise.

I ran a T5 behind my hybrid. I may put a 4L60E behind the 3400, if I decide to go automatic, not because it's "proper" but simply because I want to learn about electronic tranny control and tuning the tranny performance via the PCM. In my case I'd need to run two ECMs or rather an ECM and a PCM, unfortunatly there is no OBD1 ECM that will control the 4L60E and register boost pressure, which is why I'd run $59 for the engine in a '7730 or '7749 ECM and $OD in a '7427 PCM for tranny control. But I'll likely stay manual, just because I like to row my own gears.

The only difference between a 700R4 and 4L60E is that the 4L60E uses a PCM to control shifting, where as the 700R4 is mechanical, otherwise they are for all intents and purposes the same tranny.

I think you might be thinking that you would need to run a PCM from a '93 to '95 F-body to run a hybrid which is simply not true. It would work, but not necessary. You can use a '7730 runing $A1, which is an N/A 660 FWD code, that is set-up for DIS, and would likely run it well untuned. This uses a mechanical tranny as well, a 3T40, AKA TH125C, has TCC control, if you get the proper chip for automatic, since $A1 was also used with manual trannies as well.

There are many "proper" or "correct" ways to do this, just don't get so fixated on this tranny deal, 700R4, 4L60E, TH350, T5, T56, TKO, etc, they are all the "correct" tranny to have behind a 3.4, especially a hybrid, since you're now creating your own combination.

[Jaxom]

That's why I stressed..."wanted" rather then "needed". Contrary to other's that will argue the point, I grasp what you are saying. Luckily, I found a guy semi local that's selling both tranny's. Per your advice...and I am listening, I'm gonna go with the 700R4, since it will be sometime before I can garage the truck and do the engine swap.

So...can I get some advice on the transfer case? Neither my Haynes or Chiltons tell ya how to drain or fill it, although the haynes tells ya what fluid to use. Since the trans and other bits have been so badly maintained, should I concider having the transfer case rebuilt, or replaced with a beefier one..if availbe?

I also just spent a half hour on Amazon.com, is there any book dedicated to rebuilding just the 660's? Ya know, something like a step by step guide type thing?

[neo71665]

There are fill and drain plugs on the t-case kinda like on a rear end.

About the only real problem you see with t-case is chain stretch and you'll be able to hear that. If its not acting or sounding cranky I would just change the fluid.

There used to be a book out but its long out of print. From what I hear its ok at best anyways.

[Jaxom]

When I drive the truck, I have this feeling that I'm grinding metal. I'm assuming most of that is coming out of the trans right now. Wish I had more training with all this stuff!

[Bouche]

ok dont mean to ruin your thread but there is no point in making a new one since im in the same boat. if i swapped my 2.8 in my 87 blazer for a 3.4 i could use my 700r4 (i think thats what i have its a manual) and i could use everything else for the 2.8? as far as fuel injection goes? would it pretty much be just swapping the engines?

basically what i need to know is could it be something i could do in a normal garage not a shop? i mean, i live in the suburbs ha

[neo71665]

Quote: Originally Posted by Bouche

ok dont mean to ruin your thread but there is no point in making a new one since im in the same boat. if i swapped my 2.8 in my 87 blazer for a 3.4 i could use my 700r4 (i think thats what i have its a manual) and i could use everything else for the 2.8? as far as fuel injection goes? would it pretty much be just swapping the engines?

basically what i need to know is could it be something i could do in a normal garage not a shop? i mean, i live in the suburbs ha

Just use all of your 2.8 parts on the 3.4 block. The 700r4 is a auto tranny BTW


If you have the room to get the engine out of the truck you can do it in a tent if needed.

[The_Raven]

Quote: Originally Posted by neo71665

Just use all of your 2.8 parts on the 3.4 block. The 700r4 is a auto tranny BTW


If you have the room to get the engine out of the truck you can do it in a tent if needed.

Or outside, like when I swapped the Franken60 into my Jimmy.

The 3.4 swap is essentially just like swapping another 2.8L in, other than the need to swap the intake, timing vover and oil pan. Although in later trucks that are equipped with serpentine belts, I think you just need to swap the water pump. Sorry it's been a while since I played with the RWD 660, and I don't remember all the little details.

[neo71665]

Quote: Originally Posted by The_Raven

Or outside, like when I swapped the Franken60 into my Jimmy.

The 3.4 swap is essentially just like swapping another 2.8L in, other than the need to swap the intake, timing vover and oil pan. Although in later trucks that are equipped with serpentine belts, I think you just need to swap the water pump. Sorry it's been a while since I played with the RWD 660, and I don't remember all the little details.

I'm keeping the camaro water pump since its a shorter nose and I already have electric fans.

[The_Raven]

Quote: Originally Posted by neo71665

I'm keeping the camaro water pump since its a shorter nose and I already have electric fans.

Yes, but most people doing this swap will want to retain the original mechanical fan, especially for ease of swapping. Eletronics scares some people.

[Bouche]

cool thanks guys. this is a pretty new idea for me so i got a lot of questions. ha

[Jaxom]

Electronics scare some, eventhough I'm still learning, I'd swap everything I could to electronic not just the fan.

[ezrollin561]

Haven't posted for a while but have done the 2.8/3.4 swap and retain the 700r4.One's electronic and the other isn't,no need to complicate things.Go with the sepentine off your 2.8,you'll need the timing cover with it,water pump rotates opposite.Listen to the Raven,he won't steer you wrong.