68' M715, AKA "Smokey" (Can I post this Jeep on MUD?)

Discussion in 'HardCore Corner' started by Rock40, Mar 13, 2018.

  1. Rock40

    Rock40

    Messages:
    1,428
    Media:
    7
    Albums:
    3
    Likes Received:
    1,075
    Joined:
    Feb 21, 2012
    Location:
    Snohomish, WA
    It’s done.

    61C18495-DDB4-4E48-9A36-C0874FAB871D.jpeg

    42F1C22B-254F-4733-A297-8434B859C540.jpeg

    8C6F4384-0969-4917-922D-9A71C194374F.jpeg
    Unfortunately, picking this up with the forklift like they did proved to be unwise. The rear shock cross member completely crushed and bent. It was likely coming out with the links and coils anyway but I wasn’t too happy about it. In the end it turned out OK as I worked a deal for the blaster to take the stock M715 axles and blast the cab for free. Looking at the frame, it still appears straight, I’ll confirm at a later date and correct if necessary
     
    Last edited: Mar 16, 2018
    GLTHFJ60 likes this.
  2. Rock40

    Rock40

    Messages:
    1,428
    Media:
    7
    Albums:
    3
    Likes Received:
    1,075
    Joined:
    Feb 21, 2012
    Location:
    Snohomish, WA
    Cab back in place.... BF7C3877-7CE1-4972-9C7E-ABAF76C30E73.jpeg
     
  3. Rock40

    Rock40

    Messages:
    1,428
    Media:
    7
    Albums:
    3
    Likes Received:
    1,075
    Joined:
    Feb 21, 2012
    Location:
    Snohomish, WA
    Drivetrain mock-up today....

    F5CC7FEA-C969-4F90-B6B1-9218DBEFE775.jpeg

    6FF36524-B321-46C6-ABFA-B1C1AA068BB9.jpeg

    The 8.1 liter is HUGE. With this spacing, I believe I can squeeze a radiator in. If not, the firewall will need a bit of massaging to get the engine rearward a bit more.

    2A57ADB4-D745-4182-AC1E-9521DAF53C7D.jpeg

    Popped a Saginaw box on the frame. The stock M715 steering box was full manual. Looking at the input on the box, I think the steering shaft will likely need to be a two piece design with a pillow block bearing. It'll go though.

    E2D0EE94-1483-4E4C-BB23-65032BCD9FDF.jpeg

    Looking down at the SM456 from the cab. It lines up well with the Ranger OD in front of it. Of course the floor is going to get modified for the 5 shifters required for the drivetrain.
     
    Last edited: Mar 17, 2018
    Ronny Grady likes this.
  4. Rock40

    Rock40

    Messages:
    1,428
    Media:
    7
    Albums:
    3
    Likes Received:
    1,075
    Joined:
    Feb 21, 2012
    Location:
    Snohomish, WA
    2E4EA360-3F82-4939-8EE7-10A48227EF83.jpeg

    So sweet! There's room enough as is to more or less have a flat belly. The SM465 is about 3/4" below the frame rail and the NP205 is about 1/2" low. Better then I was expecting and I guessed on the ORD Magnum clocking.

    96D35FF5-A650-4DD5-94CD-99146C086C11.jpeg

    Green paint mark on the very lower edge of the NP205 shows where the belly would be completely flat.

    5416A8A4-CB21-4A68-83A3-5C32C6031901.jpeg

    Showing the centered drivetrain between the frame rails.
     
    Last edited: Mar 17, 2018
    Ronny Grady likes this.
  5. Rock40

    Rock40

    Messages:
    1,428
    Media:
    7
    Albums:
    3
    Likes Received:
    1,075
    Joined:
    Feb 21, 2012
    Location:
    Snohomish, WA
    Problem areas. The biggest issue is the front differential housing. Not really fair because the M715 axle won't be used but I suspect the same for the ProRock 60. Maybe worse due to the high pinion.
    CDDC6062-086C-4965-8C1E-00CBD02349B0.jpeg

    826E93A1-1BD2-4A55-973B-07A0D1C088E7.jpeg

    There is very little room between the oil pan and differential housing. Granted, the engine could still be moved up in the frame rails some but want to keep the center of gravity low along with the lift. At this point, I'm considering mocking up the stock GM Kingpin 60 to see it relates. Probably will next week. Overall, things could be a lot worse trying to get this much drivetrain in a 50 year old truck.
     
    Last edited: Mar 17, 2018
    Ronny Grady likes this.
  6. WesternCruiser

    WesternCruiser

    Messages:
    8
    Likes Received:
    1
    Joined:
    May 2, 2008
    Location:
    Biloxi, Mississippi
    Looking great, Ross! I'm very interested to see where the stock Dana 60 differential will land (the modern kingpin version), as a starting-point; between that and having a Pro-Rock example on hand, it should be easy to see how close things will be. It IS nice to see those spool stands in use--glad we didn't toss them! That Magnum looks like it'll make adding a cross-member very easy, which is nice. Great work!
     
  7. Rock40

    Rock40

    Messages:
    1,428
    Media:
    7
    Albums:
    3
    Likes Received:
    1,075
    Joined:
    Feb 21, 2012
    Location:
    Snohomish, WA
    Stuffing an engine this damn large into an engine bay designed for an inline 6 is proving to be...challenging.

    This is the passenger side manifold. As is, it's mashed into the firewall and the engine REALLY needs to move back some more to be able to run a radiator/fan combination capable of cooling this beast. Prior to this pic, I added a slightly larger that 1" body lift to help alleviate things some. The EGR bit is really the issue as the manifold is longer to incorporate it. The options were hacking into the firewall bigtime or modifying the manifold...
    F2E6622F-37AE-4004-8938-B3CA34EB8943.jpeg

    659B0D81-0451-4B30-A8CC-B9DF2D2C9E03.jpeg
    Drivers side manifold, because it lacks an EGR port on this side, clearance is not an issue.

    84E8D975-655D-4646-BA49-12B7967BBE4D.jpeg
    Modified manifold with the EGR port deleted and the flange turned down (toward the ground) about as far as I could. I'm hoping there will be room now once the firewall is clearance/modified so that the valve covers/heads will fit.

    The plan is to have a professional welder friend of mine put the manifold back together with some silicone bronze. We'll cross our fingers and hope it holds.
     
    Last edited: Mar 20, 2018
    mr jits, 2fpower and 74fj40 like this.
  8. Rock40

    Rock40

    Messages:
    1,428
    Media:
    7
    Albums:
    3
    Likes Received:
    1,075
    Joined:
    Feb 21, 2012
    Location:
    Snohomish, WA
    Firewall modification day...

    D012D22A-AC0E-47AA-9F98-22B8045ABF9A.jpeg

    Making some cutting marks

    FC7F4524-9B69-4167-8F44-FCBC96E9BEB8.jpeg

    0B89FC59-EE29-4930-B93C-08E3A7F5ACDA.jpeg

    71793D46-6C4D-4C4C-AE29-E19DFB85870B.jpeg

    Ultimately this should be close, very close. The engine has been raised about 2.5" inches and pushed back about 1.5" inches. There's now approximately 7" of room for the fan and radiator combination.
     
    Last edited: Mar 23, 2018
  9. Rock40

    Rock40

    Messages:
    1,428
    Media:
    7
    Albums:
    3
    Likes Received:
    1,075
    Joined:
    Feb 21, 2012
    Location:
    Snohomish, WA
    6614192A-ACB7-41F5-A97A-B7CFC2B7F76E.jpeg

    The plan is to pull the engine back forward about 1/4" from where it's currently at. That'll make a bit more room between the firewall and exhaust flange so the floor isn't getting cooked.

    4ADF19C2-B0CF-4C2B-99BE-D81D6F603060.jpeg

    These are the cuts, they're not cleaned up yet but overall, not too bad

    7F919D86-DC94-4ADA-B86B-3CAFE0C75BE0.jpeg

    D85A1ACC-C516-40B9-8940-771D7E641D0A.jpeg
     
    Last edited: Mar 23, 2018
    Ronny Grady likes this.
  10. CreeperSleeper

    CreeperSleeper SILVER Star

    Messages:
    6,747
    Likes Received:
    599
    Joined:
    May 16, 2005
    Location:
    Forest Grove, OR
    Just cut it all out and build your own firewall...
     
    Rock40 likes this.
  11. Rock40

    Rock40

    Messages:
    1,428
    Media:
    7
    Albums:
    3
    Likes Received:
    1,075
    Joined:
    Feb 21, 2012
    Location:
    Snohomish, WA
    There is a real danger, don't tempt me...
     
    74fj40, 2fpower and A10Driver like this.
  12. CreeperSleeper

    CreeperSleeper SILVER Star

    Messages:
    6,747
    Likes Received:
    599
    Joined:
    May 16, 2005
    Location:
    Forest Grove, OR
    Hahahaha! It's amazing how easily things can spiral out of control. It sure looks like a tight fit! I'm interested to see how you design it to keep the engine cool and protect the passengers from radiant heat.
     
  13. Rock40

    Rock40

    Messages:
    1,428
    Media:
    7
    Albums:
    3
    Likes Received:
    1,075
    Joined:
    Feb 21, 2012
    Location:
    Snohomish, WA
    Yeah, it'll be a trick. The plan is to place some sort of radiant material (Dynamat or similar) on both sides of the firewall to prevent cooking. The floor of my 40 gets so hot on long road trips that I have to wear sandals in the cab to keep my feet ventilated.
     
    whitey45, Jason Reed and A10Driver like this.
  14. Rock40

    Rock40

    Messages:
    1,428
    Media:
    7
    Albums:
    3
    Likes Received:
    1,075
    Joined:
    Feb 21, 2012
    Location:
    Snohomish, WA
    Started the fab for the rear crossmember which will mount under the Dana 300 AA adapter. 3/8” for the main plate, 1/4” “wings” followed up with 3/16” wall 2” square tubing.

    9FC11D68-E4DA-41DB-9240-C2655DC2F3B0.jpeg

    The plan is to TIG weld this all out to ensure good penetration and hopefully less warping

    F6956D62-D6B5-45B3-AD47-8A2A8CFE8749.jpeg

    Drivers side leg is now done. Frame will be scab plated as shown. On to the passenger side now which will be a bit tougher given the fact that the mount needs to clear the front driveshaft

    768270AE-D873-4DD5-A260-0A8A172C6575.jpeg

    CDB1A010-6CA5-4208-AC11-98B8070864AB.jpeg
     
    mr jits likes this.
  15. Rock40

    Rock40

    Messages:
    1,428
    Media:
    7
    Albums:
    3
    Likes Received:
    1,075
    Joined:
    Feb 21, 2012
    Location:
    Snohomish, WA
    Plugging away....
    67C7AE42-B973-44A1-AFFA-96EAF5A58B54.jpeg

    Removed the awful dual battery mount behind the drivers seat which was obviously a military “addition” at some point. Most of the bugger welds actually burned through the cab. Found a lifetime of crap under it
    37107EB1-7D9C-4D05-A95C-2E7C99082499.jpeg

    Also fixed the poor VIN plate

    1DFF6EAB-C7E2-418C-ABE9-3B8C5E20BA1F.jpeg

    View attachment 1668658
     
    Last edited: Apr 2, 2018
  16. Rock40

    Rock40

    Messages:
    1,428
    Media:
    7
    Albums:
    3
    Likes Received:
    1,075
    Joined:
    Feb 21, 2012
    Location:
    Snohomish, WA
    Crossmember complete....
    BF662D53-6771-41E1-9B8A-78A7F31DEC08.jpeg


    8A98BBFA-BDDF-4E8D-852D-26F36F51A69B.jpeg
     
  17. Rock40

    Rock40

    Messages:
    1,428
    Media:
    7
    Albums:
    3
    Likes Received:
    1,075
    Joined:
    Feb 21, 2012
    Location:
    Snohomish, WA
    ACC3FDD1-8905-4FED-9D04-5492DEFBDD24.jpeg

    The level approximates the front driveshaft, since the drivetrain will all be above the frame, the crossmember needed to go up and over the front driveshaft

    C42B6F96-61AC-4CD2-B58C-ECB5AC546F56.jpeg
     
    Ronny Grady, 2fpower and GLTHFJ60 like this.
  18. jlclar09

    jlclar09

    Messages:
    1
    Likes Received:
    0
    Joined:
    May 17, 2018
    Location:
    Covington KY
    I have a 68 M715 and I am also getting ready to install an 8.1 Vortec in mine. I currently have a 350 SBC and SM465 in mine. I am debating on using a ranger box like you did and keep the SM465 or use the Allison 1000 that is in my donor truck... decisions... looks great!!!
     
  19. Rock40

    Rock40

    Messages:
    1,428
    Media:
    7
    Albums:
    3
    Likes Received:
    1,075
    Joined:
    Feb 21, 2012
    Location:
    Snohomish, WA
    Cool! sounds pretty similar. Depending on your tire size, I'd seriously consider an overdrive either with a Ranger or the factory transmission. This project is still slowly moving along, I'm just a bit bogged down with other projects that jumped in front of it for the time being.
     
  20. Rock40

    Rock40

    Messages:
    1,428
    Media:
    7
    Albums:
    3
    Likes Received:
    1,075
    Joined:
    Feb 21, 2012
    Location:
    Snohomish, WA
    Time for an update:

    Donated the old M715 axles to the blaster in exchange for some free work
    A94ABBE6-7BC1-44A5-9D01-5E3BD9F4C7BB.jpeg

    2A00E6DA-70CD-46C0-929E-C5F1D6316879.jpeg
    Got the cab blasted. Not too bad overall for 50 year old metal
    A93B791C-1428-4765-9E2C-35FE965E6047.jpeg

    3110B870-5049-48D3-BC1B-350BDBF3A889.jpeg
     
    mr jits, Ronny Grady and 2fpower like this.
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.