In the beginning stages of building a stretched 40 and considered a few frame options and largely landed on building a frame from scratch. Not super interested in stretching an actual 40 frame, most are pretty rotted around here, and I would need some modifications to suit the front 3 link I am building it with and notch the rear for coilovers, among other things. Looked at the Aqualu stretched frames, they look nice and add some clearance for panhard/drag link in the front as it doesn't droop back down, but they are expensive because of shipping and not quite what I wanted. Looking for around 12-14" of frame and body stretch, and trying to keep it low-slung with ideally 5" of up-travel. So instead I have been working on designing a frame to build from scratch myself. I have never built something like this before and would greatly appreciate any advice or calling out any issues or areas that could use improvement with my design that any of you may see. I am in no way a professional, I am YouTube Certified in everything I do, so I am sure there will be some things.
I have a crude level of familiarity using CAD, and SketchUp is the software I am most comfortable with at the moment and it has been great for visualizing stuff and testing for engine fitment (Rig is getting a merc OM606). I also have bend-tech and will be using it more once I get the design more finalized before starting to build it. I managed to find an existing CAD model of a 40 frame online that seems pretty dang accurate when comparing measurements on frame schematics I found online, and have largely used it as a reference for designing my own frame.
Right now, I am liking the idea of using 2x4 1/4 wall rectangular tubing for the the middle horizontal portion where the frame end link mounts will all be welded to. Then, coming off each end with 1.75" DOM, either 3/16 or 1/4 wall. My JD2 M32 can apparently handle 1/4 DOM, I am leaning towards that for extra beef. Frame rails will each be straight all the way front to rear to simplify making them, but slightly angled apart towards the rear like most frames like the 40's, but a bit narrower at the rear to make more room for coilovers. The rear bumper is something I am already a good ways into building and will have an integrated witch mount and through-hole. How exactly I am reinforcing this area and cross bracing the frame, I have not decided yet. The front "stinger" will be integral to the frame, and will likely be welded up with a inner solid sleeve somewhere behind where the grill hoop ties in. Needs to be beefy, I plan to have some sort of clevis mount or other type recovery point near the front of the frame. The grill hoop may or may not be removable, have not decided. Tube fenders will tie into the front hoop and will be removable.
The other way I was considering doing this is similar to the Wide Open Designs Jeep Tube Frame and just making it all out of tube. I could probably pull it off, but I feel the square tube method will be easier for me to keep things square on.
So anyways, here is where I am currently at. I have not put a ton of effort into making it look clean as I know I will be starting fresh once I can take some real world measurements this spring. There's a few link brackets plopped on I was playing with, may be mounting the rear frame uppers above the frame rails as shown to get more separation. Goal is to have a flat belly, the split case will be clocked up to hopefully be close to flush with bottom of frame. Instead of having two sections of tube coming off the front, I currently have one that will be reinforced by a piece of 2x6 cut to fit. This will need some adjustment, I am hoping to have that 2x6 situated so that I can weld the drivers side motor mount to it. I also think I have it too far back and may hit the footwell, need to confirm some measurements this spring when I can dig stuff out. Front end should be getting more reinforcement as I hope to tie the front hoop into the roll cage and will have some sort of hoop for coilovers that can tie in as well. Sitting at about 22" of belly height (this includes about 1" of extra clearance shaved off the bottom vs the 40 frame) and looks to clear about 5" of up-travel with 37's. Panhard for the front will likely need to be bent like an 80 panhard to clear the radiator fan on the 606, but should have plenty of clearance from the frame for panhard and drag link. I may even drop the front down an inch or so. Planning on building axles using Ruff Stuff 9.5 housings, but may need to go to an 8" HP for the front depending on how much room I have.
Here are a few with the engine and axles in place. The nice thing about the slant OM606 and offset split case is I can shift the engine over like the 2F was and make more room for a top link on the diff side.
And a few with a bit of body on it... playing with fender height to get more up travel. may end up cutting into the hood.
I have a crude level of familiarity using CAD, and SketchUp is the software I am most comfortable with at the moment and it has been great for visualizing stuff and testing for engine fitment (Rig is getting a merc OM606). I also have bend-tech and will be using it more once I get the design more finalized before starting to build it. I managed to find an existing CAD model of a 40 frame online that seems pretty dang accurate when comparing measurements on frame schematics I found online, and have largely used it as a reference for designing my own frame.
Right now, I am liking the idea of using 2x4 1/4 wall rectangular tubing for the the middle horizontal portion where the frame end link mounts will all be welded to. Then, coming off each end with 1.75" DOM, either 3/16 or 1/4 wall. My JD2 M32 can apparently handle 1/4 DOM, I am leaning towards that for extra beef. Frame rails will each be straight all the way front to rear to simplify making them, but slightly angled apart towards the rear like most frames like the 40's, but a bit narrower at the rear to make more room for coilovers. The rear bumper is something I am already a good ways into building and will have an integrated witch mount and through-hole. How exactly I am reinforcing this area and cross bracing the frame, I have not decided yet. The front "stinger" will be integral to the frame, and will likely be welded up with a inner solid sleeve somewhere behind where the grill hoop ties in. Needs to be beefy, I plan to have some sort of clevis mount or other type recovery point near the front of the frame. The grill hoop may or may not be removable, have not decided. Tube fenders will tie into the front hoop and will be removable.
The other way I was considering doing this is similar to the Wide Open Designs Jeep Tube Frame and just making it all out of tube. I could probably pull it off, but I feel the square tube method will be easier for me to keep things square on.
So anyways, here is where I am currently at. I have not put a ton of effort into making it look clean as I know I will be starting fresh once I can take some real world measurements this spring. There's a few link brackets plopped on I was playing with, may be mounting the rear frame uppers above the frame rails as shown to get more separation. Goal is to have a flat belly, the split case will be clocked up to hopefully be close to flush with bottom of frame. Instead of having two sections of tube coming off the front, I currently have one that will be reinforced by a piece of 2x6 cut to fit. This will need some adjustment, I am hoping to have that 2x6 situated so that I can weld the drivers side motor mount to it. I also think I have it too far back and may hit the footwell, need to confirm some measurements this spring when I can dig stuff out. Front end should be getting more reinforcement as I hope to tie the front hoop into the roll cage and will have some sort of hoop for coilovers that can tie in as well. Sitting at about 22" of belly height (this includes about 1" of extra clearance shaved off the bottom vs the 40 frame) and looks to clear about 5" of up-travel with 37's. Panhard for the front will likely need to be bent like an 80 panhard to clear the radiator fan on the 606, but should have plenty of clearance from the frame for panhard and drag link. I may even drop the front down an inch or so. Planning on building axles using Ruff Stuff 9.5 housings, but may need to go to an 8" HP for the front depending on how much room I have.
Here are a few with the engine and axles in place. The nice thing about the slant OM606 and offset split case is I can shift the engine over like the 2F was and make more room for a top link on the diff side.
And a few with a bit of body on it... playing with fender height to get more up travel. may end up cutting into the hood.
