I have an 85 CJ-7 and want to swap the engine. I was thinking of buying a late 80's or early 90's chev 1/2 ton 4X4 with a V-8 in good running condition and rusted out body and basically stripping everything away as to make sure I still have an engine and trans that still runs with wiring, computer etc.. all still connected. All I need to buy would be a Dana 300 transfer case adapter and V-8 engine mounts. Are there any particular years to look for in a donor vehicle?
You forgot the custom wiring harness. With a carbureted engine this is pretty simple, but those are older than the year range you are looking for. Price a fuel injected wiring harness before you get too involved. Let's see, you also have to buy something for the exhaust system, possibly shorty headers to make it work. Shifter and clutch linkage. Custom intake. Think about the whole project before you buy that old pickup and start swapping parts. Throttle linkage is maybe a cable, but do you have the right ends for it?
Bill, I think that's what he's saying, a "Dana 300 transfer case adapter" for his transmission. It's not as simple as it seems. Lots of these transmission to transfer case adapters require you to install a custom (pricey) mainshaft or do something brutal like cut your own to fit. I am not trying to throw water on this plan but a professional rebuilt AMC 6 cyl. is a nice no-brainer alternative. Still, a police interceptor 454 or one out of a Corvette...
As I understand it from advance adapters and Novak their kits give you everything you need to mate the Dana 300 to whatever tranny. For example for the GM TH350 the kit is around $550.00 and includes "We also supply a mounting provision on the bottom of the housing to bolt- on our heavy duty transmission mount (716021). The adapter kit includes an adapter housing, 27 x 23 spline spud shaft, bearing, snap rings, gasket, o-ring, fastening hardware and adapter instructions" and with the tranny/V-8 the length is the same as what I have now so driveshafts do not have to be altered. I can get a used truck for around $1200.00 with good running gear and still inspected. I have a BM sport shifter already. I would like to know is there any reason to choose one truck over another. Ford or chev? chev 700R4/ th400/th350? What years had which tranny. What I see a noticeable difference between a 305 or 350? Thanks again.
The 350 is bigger and just as reliable as the 305, so you might as well have that. The Chevy conversions are a little more popular, so odd bits like the shifter, motor mounts, headers etc. are going to be more common and maybe fit better. A FI wiring harness is going to run you as much as the adapter kit. It is better to get one than to try to graft your donor engine wiring harness into your Jeep. Make sure to get the computer and any body mounted sensors before sending the donor on to the recycler's. What are you planning to use for a fuel tank? The Chevy FI fuel pump is in the tank. Outside the tank conversion pumps are available, but they are not considered as reliable as the OEM setup.
That adapter kit with the "27 x 23 spline spud shaft" uses a 4x4 transmission. If you try to make this work with a transmission out of a two wheel drive truck, it won't. Then you would have to replace the mainshaft, not a big deal if you have been inside a Turbo-Hydromatic before. The TH400 is legendary for strength, although the newer 700R4s aren't too bad. If you get a 4x4 Chevy pickup, it uses the same NP231 as the Wrangler and Cherokee, although clocked the other direction, like a Dana 300 in a Jeep. We have to think about this a bit, but it is possible that an adapter kit isn't even necessary.
Try to avoid adapters altogether. Advance Adapters makes some great stuff but I watched a buddy go through a bunch of expensive transmission-to-transfercase spud shafts in his YJ. It was a real weak link. If at all possible, get parts that were made to fit together. It's cheaper anyways.
What side is the front driveshaft? Solid axle Chevy trucks have a passenger side front driveshaft (NP203, NP205, NP208, NP241). IFS Chevy trucks have a drivers side front driveshaft (NP241). A good transmission will be a TH700R4 (4L60) from a 1988 or newer truck. Avoid the older ones that were weaker. At some point in the early
90's they went to the 4L60E that will be more complicated to wire up. TH350s and 400s are great if you don't mind not having overdrive.
If you use a donor car or 2wd truck, 4x4 tailshafts for a 700R4 are about $30 on ebay. A local transmission shop quoted me $200 to put one in. Then it'll bolt right up to a transfer case.
I've recovered the EFI wiring from a couple of fuel injected vehicles before and it's not that bad. Just remove the car wiring from the engine wiring one piece at a time. Start it periodically to make sure it still runs. What's left, label it all very carefully, wrap it up, and swap it into the donor car. Before you pull the engine, have the whole harness draped over fender with the engine running right and the check engine light off. I've used Painless Wiring EFI harnesses twice ($400-$600 each!) and both times they were wired up wrong.
I think you're on the right track with buying a whole donor truck. Buying an engine for a swap from a boneyard sucks because they cut everything when they pull them.
It's a huge project. It will take a lot more time and money than you anticipate. It's also a lot of fun.
My CJ-7's is on the pass. side. Are you saying just to use the whole setup from a solid axle chev 4wd truck, transfer case and all? Does it matter that the donor truck may have had auto locking hubs and mine has manual? what about gearing, will the different chev. transfer cases be similar to my dana 300, it would be nice if they were a bit lower because I have 35" tires and stock 355 differential gears. Also do they rotate in the same direction as my current jeep's drivetrain?
No. It does matter if the donor has one of the full time systems and full time hubs though. You don't want that.
This is one place where Advance Adapters can help you out. Their various "Conversion Manuals" have all the gear ratios, spline counts and other bits of information you want. They were only ten dollars last time I checked. Get the Jeep Conversion Manual and the one for full sized Chevys too.
I believe so. You want to look at the pinion to see which side of the ring gear it sits on, but I believe so.
I hadn't thought about that. I'm putting a V8 and Dana 44's under a Toyota at the moment and wouldn't that be a shock if the front tires spun backwards!
You'll need to have driveshafts made, but otherwise, yes. The alternative is to keep the Dana 300 and buy an adapter. There are good points to both.
Like Earle said, avoid the full time 4x4 models. Older Chevys had either the NP203 full time case (avoid) or the NP205 part time case. The NP205 is the strongest but it is really heavy. Newer Chevys have the NP208 or NP241 which are chain driven aluminum part time cases. They're a lot lighter and a better choice unless you do serious off roading.
If you drag home a 1990 Blazer, you'll get a 5.7L TBI V8, 700R4 4- speed auto, and passenger side NP241. That's a great combination.
In 2-Hi, the transfer case is 1:1 straight drive, so it won't make any difference. I've heard the Dana 300 has a better low range than most other transfer cases so you'll be giving up a bit of gearing in 4- low. On the other hand, the V8 has big time low end torque so it will launch much stronger even with stock gearing.
I believe so, but it's definitely worth checking before you get a very unpleasant surprise.
An NP203 would at least be interesting for swb Jeep use because of its interaxle differential. But the poor low range would reduce off-road utility. Which would you rather have, road-hugging ablity or a good crawl ratio? These fulltime systems make people over confident in snow and ice. I would like to have one in my Wrangler, of course, but IMHO not worth the added work and length. Wish I could stop thinking about it though.
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Good link for this stuff. They make this point, "GM cars and trucks are even more common and inexpenive than Ford parts." That is why you would go GM, and the running gear is not bad either.
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