47-55.1 51 Chevy on a Ford Explorer Subframe - Time for a Different Frame Swap!

[Thadious]

So... having already worked with an S10 extended cab long box swap on a 47 (my previous build that I sold when I left Victoria) I learned a lot along the way and it was on a very tight budget. One of the things that I truly didn't appreciate was the narrow track width in the front and the requirement to run spacers to push the wheels out. I know that many have and do use them, but something in me just doesn't like the added torque on the spindles that these would cause.... it's just me.

So... with that being said... I've looked at using an Explorer 8.8 LSD rear end and then went down the path of looking at the front as well (keeping the stock track width that the explorer has and just using the entire subframe (although I am aware that I will need to extend it (which I find no big deal)). This is expected to give a better track width that would only need to be corrected with wheel offsets to get me to where I want to be.

And that leads me to my donor vehicle... it's a 2003 Explorer Eddie Bauer edition with the V8 motor (no, I'll be using a 91 TA L98 TPI 350 with an NV3500 behind it). The explorer has 4 wheel disk and a 3.73 D4 LSD in the back with IFS and IRS. Paid $400 cdn for the donor and the cost to go get in the next town over.

Kermitt47, this is your fault! After watching the video and seeing his setup... I knew it was doable... and so... I will be doing! Here is a link to the video... https://www.youtube.com/watch?v=uj078sfLnhs

The "Project"


The "Donor"

[NorCalGal]

I’m in! Love looking at new ideas.

[Kermitt47]

I am in for the ride. I had originally found the video when I was looking for Gen V swaps and at the time thought the Explorer chassis was worth a look at a later time. I will be happy to follow along with your build.

[Father&son56project]

Thadious: That looks like a very interesting swap option for a lot of older trucks. Post lots of pics and details about what you do to make it all fit together and work right. I will be watching this one with great interest.

[joedoh]

nice stuff! starting with a long bed box you can make the wheelbase exact without stretching the frame! although it looks like a 9ft bed so it and the running board would be something other people would be looking for.

I am in!

[Thadious]

The one pictured is a long bed, but I will either be shortening it to a short bed or using the short box that I already have. All the bedrails and strips need to be replaced anyways and the short running board that I have are a little rotten. I'm on the fence on shortening the box to actually fit the wheelbase that I have (and consequently the running boards and filler panels), going with a standard short box and moving the fenders forward to match the wheelbase (and shortening the running boards and filler panels) or stretching the frame (most likely) and just using a short box, fillers and running boards...

I'm trying to use what I have instead of spending a ton on new sheetmetal, but we'll see where that goes!

The wheelbase on a 2003 Explorer is about 113", so about 4" less than optimal, but shifting the fenders forward may be an option, rather than extending the frame... we'll see.

And on another note... an S10 frame (at the back of the cab area) is about 40.5" whereas the the Explorer frame is about 45"... so I will likely be looking at opening up the back of the cab a bit to accommodate (about 2" per side).

[dsraven]

are you saying you will be extending the cab to fit the wheelbase and box length you want? its a bit of work but would give you more leg room. I suggest to add length to the doors and move the posts back. it may look better than a short extension behind the door. it is your truck though so you gotta do what you like.
have you thought about using the donor explorer floor pan and firewall? I sent you a private message in that regard.

[Thadious]

Originally Posted by dsraven

are you saying you will be extending the cab to fit the wheelbase and box length you want? its a bit of work but would give you more leg room. I suggest to add length to the doors and move the posts back. it may look better than a short extension behind the door. it is your truck though so you gotta do what you like.
have you thought about using the donor explorer floor pan and firewall? I sent you a private message in that regard.

Apologies and let me clarify... No, I have no intention of cutting up the cab or extending it. It is a matter of shortening the box/running boards and moving of the fenders.

After a closer inspection of the frame today (and having it almost completely stripped down) I will be extending it... it will be a matter of cutting it, placing a long insert inside, drilling and plug welding it in place, then having a couple "C" channels make from 1/8" plate as fillers and welding the whole thing together.

What I will have to do, is at the back of the cab, down by the frame rails, enlarging the opening that goes over the frame so that the cab can sit down over it.

I removed the cab, fenders and entire front end of the truck off of the old frame (minus the hood) as one piece. This will help with getting everything aligned as a unit with minimal shifting of the parts.

I do believe that with some minor mods, this will make for a pretty nifty conversion.

[dsraven]

from experience, cross brace the cab in the door openings and side to side somewhere. do this when the doors fit and open close properly BEFORE you cut anything. it would have been good to do this before it was removed from the old frame but whatever, it warrants doing just to keep things "square" so with all the movement and stuff hanging off the cab unsupported the cab doesn't get tweaked and then the new mounts etc are made for a tweaked cab. I would suggest to set the cab on a square level dolly of some sort so the mounts are level with each other and then get the door hinges etc rebushed so they fit properly and then adjust the doors to the cab. when this is done, so they open and close nicely, you can drill a couple of small alignment holes in the door, the hinge and the cab where the hinges bolt up. then when you need to take the doors off for whatever reason it will be easy to get them back where they need to be. if, when fabbing and shifting stuff around, the doors don't fit then you could look for the reason why. something is stressing the cab.
since the box needs work anyway, you could think about using the floor from a newer truck that has a steel floor, sides, front wall etc. just a thought.
if you have the space keep the donor as long as possible, you never know what you might need or be able to sell for a couple bucks to pay for stuff you need. that is unless you're independently wealthy, lol.

[dsraven]

I would suggest to do a frame check on the donor before you get too far in. it doesn't look like t was banged up but a corner to corner check would be easy.

[Thadious]

As this is my first go round with an Explorer frame and the fact that it looks like a nice swap in area when it comes to space, my intention is to start with the old frame and bust out the laser level for measurements. Distance front to rear on the cab mounts, distance to the front rad support mount (looks like I may be able to cut the old one out and install it in the new frame (since I don't have the steering box to deal with) and then do all the elevations. This should get me the plan view and elevation location points for the mounting as per the original design. The largest consideration I have after that will be the height required to clear the transmission. I'd like to keep the trans hump to a minimum if I can.

I picked up the donor vehicle on monday, stripped the body off on Tuesday to this point



Someone was looking for the transmission and transfer case out of this thing so I stripped the rest of it down (for the most part) yesterday and got it to this point...



Look at all that free space for the engine in the front! Sorry that the drain pan is in the way, I was bleeding out the power steering fluid now so I didn't do it all over the place rolling it around in the future...



I also stripped out the front axle in the process, effectively making this a 2WD. I'm not a big fan of leaving the splined hole in the hubs open (after pulling the CV joints), and considering I really didn't want to pull the front end apart to get the joints out, I cut them just behind the small boot end (had to pull the boot back to do it. This gave just enough clearance to slide the remaining part of the CV joint out of the front hub and enough that I could pop the other end out of the front axle and get the axle out (after unbolting it).



And so they were machined down to this point and fitted back into the hubs, just using the original nuts.



Today, I finish pulling that massive fuel tank (I think I'll be using it since it's poly and will give a wonderful range of driving and fits right in nicely. Exhaust lines go down the other side and there's removable heat shields that cover it all. Finally a pressure wash before I roll it back into the shop and let it dry for the week while I go camping.

[dsraven]

Sorry that it's taking so long to get anything done, maybe after camping you'll feel more like working on it.
Kidding, lol. Is there more hours in a day out there in Creston? Great progress. Keep posting pics, maybe it will get me fired up to work on mine.
I need to go camping, maybe I should try Creston......

[edgeleycanuck]

Very interesting, this is something a little different, I will enjoy watching. Not sure what your plans are for actual bed length but I'll throw in my 2 cents.
I also started with a 9 foot box, I shortened it to accept the unaltered floor I salvaged from a 2000chev extended cab pickup(6.5 foot bed), it ended up being about 1 inch longer than an original 1/2 ton wheelbase. In my opinion these trucks are short and I wouldn't want to be any shorter wheelbase base than the original 1/2 ton. I also used a rotating laser to get measurements from a level original frame, worked great.

[Kermitt47]

Wow, no grass growing under this project! Great progress.

[Thadious]

Originally Posted by Kermitt47

Wow, no grass growing under this project! Great progress.

I try to keep things moving, but I'm in a bit of a lull in my home reno project for a couple days, so this filled the time. After camping, I expect that my project will slow to a day or two a week of dedicated time until the snow flies... then it's full time!

Retired at 50... gotta keep busy tho!

[Thadious]

So, after a final removal of some things (gas tank being one of them and a quick pressure washer blast...

Here are a few pics of the 2002 Explorer frame beside a properly sized (I had to shorten it since it was a extended cab short box) 1995 S10 frame. Note that the Explorer frame is fully boxed for it's entire length.











Note that the difference in frame height is alot of the difference in tire size. These are the stock size tires for the S10 vs the taller tire size for the Explorer (the Explorer size is a common choice for these builds at 29" dia).

[Father&son56project]

Thadious: Those side by side pics of the Explorer and S10 frames are great. I notice that the frame kickup at the rear of the explorer seems a little less pronounced than the S10, but those rear shock towers in the Explorer seem a tad high. I’m thinking of how the 2 frames compare in terms of the loss of bed depth, but it’s hard to tell from the pics as to which frame is better in that respect. Keep posting pics of this quality, and include LOTS of details!

[Thadious]

So, at first thought, you are absolutely correct. What I'm thinking, at this point, is 2.5" lowering springs with a spacer between the 'cup' at the top of the shock tower and the tower itself, thus effectively negating the 'drop' the springs give but removing the height above the tower. Of course, shorter shocks will be required. We'll look at this later but should give a slightly lower bed height than the S10...

[Tempest67]

Those are real good pics, Thank you.

It appears that the width of the Explorer frame may cause issues with the AD trucks, and maybe better suited to a 55.2 - 66 body ?

Thanks again, I will be following along, as I am considering a new project.

[dsraven]

As for bed height and those towers, like you said, address that issue later. When I did the 57 on an envoy donor I was all worried about bed height due to the rise in the frame above the axle. When done I thought, whatever, probably not gonna carry much back there anyway. I suggest to mock it up with a raised floor to fit the frame and think about some sort of mini tub where those towets are. The donor vehicle had some sort of bump out there which you could possibly save for later when you get around to that part. Look at some of the other builds with basically no box due to huge tubs. It just depends on your personal wants.

[Thadious]

@Tempest67 - You are correct, the back frame opening of the cab will be opened 2" on each side to accomodate the additional frame width back there.

@Dsraven - in the past, when I did the S10 swap, I raised the box, lowered the rear fenders and made new filler panels between the box sides and running boards. They didn't like out of place at all and the height of the cab above the box in the back looked more proportional.

[dsraven]

It sounds like you have a plan, I'm just saying you can install the box and figure out your floor height or floor bump over suspension parts after. Lots of guys dont worry about the floor until after they have a few miles on it, some dont put a floor in so they can showcase their handiwork.
Nice job on the front stub axles, quick too. Do you have a lathe or access to one?
My project is stalled due to other gotta do projects. Hope to get back on it soon.

[Thadious]

So... managed to get "some" progress on the ole girl this weekend. Couldn't wait to get the front end on the frame to see how she was going to fit! I found that with the additional width of the front end, the inner fenders should slip over the front suspension a little easier... well... it was a fair bit of trimming and fit, and trimming and fit to say the least!

First we had to see where the front frame "horns" needed to be bucked off so the rad support would drop down over it... this was the first location.


After a few more "fittings" when trimming the front inner, I found that it kept binding up and rubbing (cut it too close) so I trimmed it back just a little further...


It worked a fair bit better and I was able to get the body to sit down a LOT nicer on the front end. Keep in mind I had to trim out about 1 1/2" from each side at the rear where the notch sits over the frame. The inner sheetmetal was a bit rotten, so these are getting replaced anyways, as well as the typical cab corners.

A couple of the inner fender trims...
Driver's side


Passenger's side


The engine mounts are still on in these pictures, but they've been removed. The height on them is a little offset as the driver's side seem higher, but they'll be reworked anyways to fit the TPI block and NV3500 trans in.

And this is what she looks like now with the body in place...


I'm liking the look of the track width on this far more than the S10 and NO SPACERS!!! The tires on it are 28" on 17" aftermarket mustang rims, so they may be reduced in size for height, we'll see.


Next was getting the body back off and getting the frame ready for stretching... I've opted to cut the frame on both sides just forward of the front gas tank mounting crossmember. This is because I'm thinking of using the stock Explorer tank (it's a poly tank, quite large and I think I may be able to do the hidden filler neck behind the license plate route. So, levelled and on custom made stands, I used my machinist level (0.005"/ft) to get everything tickity boo. (I'll be tacking the top of the stand to the frame so they don't move when I pull the halves apart)


Then setting up the locator marks to ensure everything stays square when putting it back together.





These marks are located 11" back and forward of the front gas tank cross-member and measured from the upright tabs forward and aft respectively and 1 1/2" in from the outside of the frame. This gives a diagonal measurement of 50"

The nice parts about this location of the cut is that it can be measure from the square locating holes on both sides (with the two round holes beside it) back 6".

Keep in mind that when drawing the lines for the cut and using a square and scribe, if you put the square on the bottom of the frame and the top of the frame respectively, they aren't the same! This frame is rarely truly parallel in the same spots! This also applies to the front frame horns.

[dsraven]

Making good progress. With the stang wheels the track width looks good.
On the inner fenders, ensure to leave room for body flex. You could "shingle" it so the inner is narrower than the frame and that way it could be a bit longer to hide the gap, or cut it short and use a thin rubber flap like the newer vehicles use. That way your engine bay stays cleaner less splash from wheels.

[Thadious]

Originally Posted by dsraven

Making good progress. With the stang wheels the track width looks good.
On the inner fenders, ensure to leave room for body flex. You could "shingle" it so the inner is narrower than the frame and that way it could be a bit longer to hide the gap, or cut it short and use a thin rubber flap like the newer vehicles use. That way your engine bay stays cleaner less splash from wheels.

When I put the body down on the frame, this is about as far down as it will comfortably go. Once I get the engine and trans mounted, I'll have an idea of how far up the cab needs to be from the frame and what kind of hump I will need for the trans. I suspect I will have to raise the body a bit to clear and that may give me a bit of wiggle room for the suspension components. If not... well, we trim a bit more. I am also looking at taking another set of inner that I have and graft the two together to get a bit more inward reach and so all of the suspension components are covered. That or I will do the rubber mat interior as you indicated. We are on the same page!