Gator

Now before I ask, let me begin by stating that I know some of you think this should be criminal. I love Toyota just as much as the next guy, but I have just had the head gasket blow on my 94 X-tra Cab for the second time. It's got approx 200k on it. Had the first one done in 1998 via recall, and now the dealership is telling me I'm on my own on this one.

I just bought a house recently, and that pretty much drained my savings account so I only have about $1500 - $2000 readily available to sink into this. I am waiting to hear if the heads will need to be reworked and I have been told that if they do, then there is a good chance that the bottom end will go when we put it back together. I don't want to waste my time or money, so I am considering going forward with the swap to the 4.3L Chevy V-6. I have had 2 Astro Vans that had the 4.3L in them and they both went past 280k before any real problems. The 4.3 is very spunky and should have no problems handling any future mods I have planned.

My question is regarding the adaptation of parts. I have the topic, and have found some old links, but most cover the 22re swap as opposed to the 3vze w/ Auto trans. I have never done this sort of thing before, and would like any help anyone could provide to get me through this process. In return, I will provide detailed documentation of my project and will include as many pics as possible.

Thank you in advance for your assistance.

Gator

I just found another post that has a lot of info in it. Here is the link:

https://www.yotatech.com/forums/f147...3/#post1010847

TACO626

check out Downey off-road..... Their website shall give you some sort of idea.

Gator

Well, I just heard back from the shop and my heads came back clean.

Looks like I will be able to spend some quality time with my 3vze while I build and prepare a 4.3L for the swap. I found a donor vehicle yesterday for $350. It's a Chevy Astro Van that was owned by the State of Georgia, but had been stolen. The column is busted, but it supposedly still runs good. The guy claims to have a title, so I won't have to worry about that sort of thing. I will be going to look at it this week end and will let you know if this will be my donor or if I decide to go with another.

I remember reading somewhere about possible laws governing engine swaps. Does anyone know where I can find info on Alabama state laws covering this issue?

Gator

Well, I got my truck back from the shop this morning and I am so happy. You never realize how much you love a truck until it's gone for nearly 2 weeks.

Here is what all I had done:

1. Heads cleaned and tested - Good

2. Head Gaskets Replaced - SafetyTM Head gaskets feature graphite, graphlon coating, and multi-layered steel(MLS) materials. Graphite facing coupled with a perforated steel core can provide up to three times the temperature resistance and reduces the possibilities of burn-out, leaks, and blow-by. Graphlon is added for many applications acting as a cold flow seal and allowing movement to accommodate normal expansion without gasket fret or failure.

2. Water Pump - Replaced

3. Timing Belt - Replaced

4. Knock Sensor Wire - Tested Good

5. replace thermostat

6. replace exhaust manifold studs

7. replace all Spark plugs - Denso

8. Change oil - Castrol 10w-30

9. add oil treatment

10. Replaced various nuts, bolts, & fasteners left off by the dealership when recall was performed in 1998.


Total cost $998.08

The truck seems to have a little extra response to it, but it feels like there is a slight shimmy in it when running the A/C. It feels kind of like a miss, but it isn't noticeable any other time but at idle w/ A/C on.

Also, it runs a whole lot cooler now than it ever did before. The temp gauge never got above 1/4th on my 40 mile trek to work this morning. Used to it would stay right around the half way point. They must have used a cooler running thermostat than was used before.

mt_goat

Yeah with an auto tranny there is a lot of extra problems. The main one being the ECU controls the shifting. So you would either need the Toyota ECU to run the Chevy engine and the Chevy ECU to run your tranny. Good luck with figuring out either one of those setups. One other option would be a manual control device for the auto tranny, there is a guy that makes them and you could fab up a paddle shifter, that would be sweet.

Gator

I found and purchased my donor vehicle for the swap. Yes, even though I got the 3vze fixed, I am still planning on doing the swap. I just don't have to be in as big a hurry now that I have my transportation back.

Anyway, the donor vehicle is a 1993 Chevy Astro cargo van that used to belong to the State of Georgia. It was stolen, and recovered then sent to auction where a local guy picked it up with intentions to repair the column and resell it as a cheap work truck.

I will post more info and pics as they become available.

rentedmule

I think all of the 195 HP versions of the TBI's were vin W's, not Z's but i'm not sure about the astros. if you're building a wishlist for your 4.3 check out wynjammer.com, they make a centrifugal blower for the TBI's. As far as the tranny problems with the swap could you use a 4L60 instead of a 4L60e to avoid the ECU control issues?

Gator

Mt_Goat,

From some of the reading I have done on the Downey web site as well as in their catalog, it is recommended that you swap both the engine and tranny. They have a kit that is made for this particular swap, and they very adamantly state that they do not recommend using the Toyota tranny with the 4.3 due to the torque that the 4.3 has being more than the Yota tranny can handle. This 4.3 is supposedly putting out 165HP and 235lb-ft of torque compared to 150HP / 180lb -ft Torque. It is their position that second gear can not handle the torgue of a 4.3, and would ultimately fail.

They do have a harness that will "bolt on" to a 4.3L w/ either the 4L60E or 700R4. Neither the TH350 or TH400 trans depend on the ECM, and therefore are irrelevant to this conversation.

I believe that the van I have picked up has the 700R4 in it, so I will be using the harness they supply that will allow me to us all my stock gauges and components. They even have a box that allows you to adjust the VSS according to the trans, tires, rims, and any other variables via DIP switches in much the same manner as a garage door opener. Ain't that cool!

Gator

rentedmule,

I think you are correct. I found another link while typing my last post that stated as much, though it was in the Blazer line. Don't know if there will be much difference, but I am going to say it is the 165HP / 230lb-ft engine just to be safe.

Seeing as to how this is basically a 350 with 2 cylinders cut off, I can't wait to see what options are going to be available to build this thing up!!!!

Gator

Here is the link to the supercharger you mentioned.

http://www.tbi-superchargers.com/TBI...43_V6_Kit.html

Gator

Given the whole torque issue brought up by Downey's, I will probably just use the 700R4. I had thought about making it a manual 5sp, but I like having an auto when climbing or crawling.

I have to be careful with how wild I go on mods, or else I may be better off building a rail job and putting the 4.3 in it with a propane kit on it! That would rock!!!

rentedmule

there's definately alot of options available to wake up 4.3's if you ever decide you want more - i can even give you a phone number to order a 1000+hp turbo syclone motor if you want?! good luck on the swap!

Gator

Well, it's been a while since I've posted any progress because I haven't made much. I did get out to the garage this weekend and begin the pain staking process of trying to pull the 4.3 from the van. Let me tell you, it's a PITA! I miss the days when I was working on Camaro's instead. They were much easier to pull.

Anyway, I will hopefully have the engine out with in a couple of days and begin the process of clean up and tear down. I plan on taking advantage of the fact that the 4.3 is a 350 with two cylinders cut off. There should be alot of options when I go to put it back together. I'm already thinking about mods like boring it .030 over, roller cam & solid lifters, timing gears, over sized valves, headers, etc. I'm wondering what my options are going to be concerning intake design. I've thought about supercharging it, but I've never done that before. I want to keep some sort of fuel injection, but I'm not stuck on it. I guess I'll decide that once I get closer to having all of the machine work done.

I will post pics as soon as I get the engine out where there's something to look at. It's pretty ugly right now, I got mad yesterday and took the saws-all to the van! felt good, but made a mess.

rentedmule

The 4.3 isn't quite as simple as a sawed off 350 - the firing order on the 6cyl vs 8 cyl and keeping it balanced changed things up a bit. the stock exhaust manifolds won't hold you back until you're into the 300+ hp range. I wouldn't waste money on headers unless you go with a long-tube design, shorties won't net you anything noticable.

You'll see some good gains by switching to vortec heads off a newer 4.3. there's a few things you'll need to do to make them work but it's nothing major (check syty.net for the details). The newer valve train also uses roller tip rockers. Porting probably won't help a huge amount unless you're going to serious forced induction later on. I think Edelbrock makes an intake manifold that'll work with that combo (part #2114?).

Comp cams has a few different cam grinds that make a nice difference too. if you don't want to get into the cam SLP makes 1.6 ratio rocker arms. underdrive pullies are swappable from the 350 - check ebay, there's a good seller liquidating them for $20 right now. throttle body spacers (gasp!) also make a noticable diff on these TBI engines from what I've read on the forums.

Gator

Thanks for the info, I didn't mean to imply that it was literally a sawed off 350, but it is very similar. The info about the headers is greatly appreciated, you may have just saved me a wad of cash. I am used to building 350's and shooting for 400+ HP. It's probably obvious by my future mods signature. I've never messed with the Chevy V6's before, so this will be as much a learning experience as an adventure.

I have briefly reviewed the site you mentioned, and it looks like a good site for info so you can bet I will be eavesdropping on that forum for a while. I love Comp Cams and will definitely be looking into what they have to offer. Ebay is another favorite source of mine so it will be pillaged as well.

Gator

301HP@5500 RPM
316lb-ft.@4400 RPM



http://www.hotrod.com/techarticles/e...ild/index.html

dijlop

word. deff keep this thread going with info. ive got a bud with a new 4.3L going into his blazer, and if you can list out all the mods with prices and amount of work i can help him out. awesome thus far.

Gator

well, after reading that article, I will probably parallel the build up they did. I'm not going to go .060 over because of cooling issues, and I intend to stick with fuel injection, but there will be some definite similarities.

Any ideas what kind of vacuum issues I may face with a beefed up cam?

rentedmule

making a 300hp 4.3 is pretty straight forward with forced induction - mine is probably ~260-270 at the crank and I basically just bolted on a low-end supercharger, an exhaust, and got it tuned. methanol injection would put it close to the 300 mark.

I haven't heard much about vacuum issues with big cams but I also haven't really looked. Some guys use a hydroboost brake setup off the astro (you've probably got one on your donar vehicle) to eliminate vacuum brake booster problems but that's mostly for drag-race style turbo/supercharger launches.

as for mods and prices
new supercharger $2700 (powerdyne/wynjammer) - used $1000-2000
meth injection $300
underdrive pulleys ~$50-100
TB spacer (for cpi/tbi) $50-75

if you're really interested in forced induction there's turbo and supercharger kits for 4.3's on ebay right now.