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Budget For 4.0 Swap Into 75cj

Discussion in 'Intermediate CJ-5/6/7/8' started by FinoCJ, Oct 15, 2017.

  1. Oct 15, 2017
    FinoCJ

    FinoCJ 1970 CJ5 Staff Member

    Bozeman, MT
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    Looking into a 75 cj. The body is in good shape which is nice, and its mostly a shell on top of frame and axles. I kind of like that it has no motor or transmission/TC as that would make it a great candidate for a swap to something newer. As I understand, the the later 4.0 should drop directly into an intermediate that had a 232/258 - would this direct drop in also work with motor mounts for a 304?

    My idea is this engine would combine with AW4 xj type 4 speed auto and I am not sure what would be the best TC option - stay with the xj combination or something better? Although I would love to put a 4 speed manual in, the auto would work with the longer wheelbase (its been extended to cj6 104 inch wheelbase) and my wife would give more approval as it provides her more driving opportunity. Plus it seems a pretty tried and true set-up. Anyone with experience on this swap give any input - such as any engine bay, firewall and floor modification and shift lever issues their might be?

    Any other engine swaps that might be better than a 4.0 given the circumstance. If I have to go relocating motor mounts and all that (in addition to loosing some interest due to complexity) then certainly a sbc would be a great option.

    This would be kind of a long term project (2 years) to build and if it turned out as I would hope, it might become a replacement for my 70cj5 in terms of building a bit more aggressive wheeler - say 35s with lockers that is still driveable to and from trails. The extra space would be great! Of course, lots of other concerns to check out such as frame extension by PO and so on. Trying to determine a budget for such a project and what would be a reasonable starting investment for the existing pieces.
     
  2. Oct 15, 2017
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    It's passenger drop, and the XJ donor will be driver's drop. So I think you'll need a Dana 300 from a later CJ and maybe a clocking ring. '90-up AW4s are 23 spline and compatible with the D300. Modified Aisin-Warner AW4 Tech - NAXJA Forums -::- North American XJ Association The left frame tower is the same V8 or six, the right is different. If you need the right mount, '72-75 is a possible donor, '76 up is different. The VIN will tell you what the factory engine was.

    Regarding money, I would start adding up what I'd need. If you buy a complete donor, you can take the harness from that and thin it ... not hard, I hear. A D300, drive shafts, new exhaust system, likely you'll have to piece together the fan and water pump to get the right config for the CJ radiator. Guess at how much the donor will cost and look at what's present and missing on the CJ. The more that's missing, the more expensive the project will be. Does it have a top? Roll cage? Tires and wheels. LSD or lockers? Seats? The more that's there, the less it will cost.
     
  3. Oct 15, 2017
    FinoCJ

    FinoCJ 1970 CJ5 Staff Member

    Bozeman, MT
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    Tim - Thanks for the motor mount info. Supposedly the jeep already had a 4.0 swapped in (but not there now), but who knows what a PO did with a swap. I will look into the details of the motor mount to see what has been done.

    FWIW - I'd probably not go with a donor vehicle as I have no place to keep it - ideally buy a reman'd crate engine, or maybe pull one locally from a yard or used off CL and the like. I realize the price goes way up with all new/reman'd parts, but that is okay for initial budgeting purposes. If its too much, then I go a different direction. This doesn't have to be a 'low budget' build, it can be a more expensive build as long as it fits within my expectations if that makes sense - I am more interested to have a newer drivetrain that I won't have to worry about if I can at all afford it, as well as keep the project scope within my ability. Hadn't thought about any challenges with radiator and cooling - I assume there is no radiator now. A D300 is fine for TC (maybe with Tera Lows at some point - but CR is less critical with auto). Although not necessarily expensive, fabbing a good cross-member may challenge my skills as well as adapting shift levers and floorpan work. Driveshafts would be custom of course from TW or the like. I need to check axle info a bit more...they are not cj but rather 75 wagoneer axles (still passenger drop front I believe) reported with 4.10s (not sure how that would work with 35 - could just keep it to 33s. Assuming its all open - and I could drive it that way for while, lockers would be way down the road and could be done much later. Not sure about the current swapped YJ springs working with the axles and spring perches etc. Not sure if the frame extension is done well, and although the front horns would be boxed from factory, the extenstion to 104" would probably necessitate frame strengthening if it hasn't already been done. There isn't much inside - new soft top and jungle jim roll cage included, but no seats etc, or even much of a steering column. Not sure how much in terms of hood and front fenders are really there. I can get those from local jeep JYs, but of course adds to expense. Yes - the less that is there, the more expensive it will be to get it running, but in theory makes it cheaper to buy the initial jeep, and then I don't have to pay for stuff I am just going to throw out.

    It would be big project, way outside of anything I would normally do. But having a driving cj5 reduces the pressure as there is something fun to use, and I would probably have to spend more money than most to keep both the build time reasonable, and to buy useable parts with less fabbing and piecing of stuff together - and that is okay as long as it fits within a budget that is reasonable to me. My time and the ability to drive it in the reasonably near future has value to me, and no expectation that the selling value of the final project would be near what I invested, but of course the budget isn't anywhere near unlimited. As with all these projects, the more aspects that come to light, the less likely I am to jump in...but I don't want to buy someone else's uncertain finished project at an insane price either.
     
    Keys5a likes this.
  4. Oct 15, 2017
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    Yes, a '75 Wagoneer will have an open passenger drop 44 front and a flanged 44 rear, 6 on 5.5" circle. Note that most '75 Wagoneers got automatics with the Quadratrac, and those had offset rear axles. Even for Wagoneers, it's not clear that the offset will work with a centered transfer case, and the Wagoneer has a 109" WB.

    Just a comment - I kinda doubt, with all you'll need to do, that this project would be any less expensive than finding a decent '72-75 CJ-6, or even a '72-73 Commando. The Commando could even have a factory automatic. Might end up that the seller would have to give you money to take the Jeep, in order to justify the budget. Note thet while I was working there, Chuchua put a TH400 in a CJ-6 for a customer, and it was pretty easy. They did it with almost all new off-the-shelf parts.

    I also remember the experience of my Dad when he converted his C2500 to 454 power using a Chevy crate engine. He thought it would be an easy changeover, but there was a seemingly endless stream of missing pieces that he had to run to the local Chevy dealer and order. Cost more, took longer.
     
  5. Oct 15, 2017
    FinoCJ

    FinoCJ 1970 CJ5 Staff Member

    Bozeman, MT
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    You are probably right - although its probably not worth it, a modern 4.0 with 4speed auto would be an upgrade. A 304 with TH350 would be nice as well. I do keep my eye out for what you listed, although the bull nose commandos are ugly to me. I like the earlier 4wd jeepsters but the have a lot of the same challenges that the ecj5s have. From my initial research, this probably isn't happening. For the cost I could probably find a reasonable cj8 to work with.
     
  6. Oct 15, 2017
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    Realize that the CJ-7 got the TF9xx automatic with a Dana 300 from 1980 on. And there are a lot of Wranglers with automatics out there too. (Mmm LJ).
     
  7. Oct 16, 2017
    FinoCJ

    FinoCJ 1970 CJ5 Staff Member

    Bozeman, MT
    Joined:
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    Now you got me looking at this FS commando project from a member here - v8 with TH400 and long wheelbase and hardtop.
    1972 Commando For Sale
    Don't even have to worry about the 'ugly' to me bull nose! Probably could buy and build this project for a lot less and it would go back together a lot easier. Maybe more body work - looks okay though from here.
     
  8. Oct 16, 2017
    4wealn

    4wealn Member

    Ontario, Canada
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    FinoCJ, I have a 74 CJ5 that I put a 98 TJ 4.0 in. It was a very easy swap. I was luck and had the complete donor TJ. I did not want to play with the harness myself as I have never done it even though many told me it was easy. I sent it to Hot Wire Auto and they did a great job. It was a complete plug and play when I got it back. Take it, it was not that cheap $800 to have done but I got the donor TJ for free.
    The motor mounts will work off the block. The TJ 4.0 has the motor mounts in a different location but the original bosses are still there as the block is still pretty much the same since the early 70's. I am sure Tim can shed some light on that. I purchased new mounts and it fell right into place.

    I still have the original length of the 5 so I am running a T18 with the Dana 20.

    Let me know if you have any questions on the swap if you go that route as I have been through it all. It would be a pleasure to help out if I can.
     
  9. Nov 5, 2017
    rejeep

    rejeep Well-Known Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Rochester, NY
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    Find an 304/auto CJ7.... Done
     
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