The Stovebolt Site Forums The Shop Area General Truck Talk looking for a stronger frame

I've got a '53 3600 and I'm looking for a stronger frame. I want to convert over to 4x4 with a stronger engine and transmission but I know the original frame doesn't have a prayer for the diesel torque I have in mind. Does anyone know of a frame that will swap under the truck without too much fabrication? I can work metal but I prefer to spend my time on other things. My other thought is to have a new frame made but that can be expensive proposition.

For my project I decided that the 1 ton frame I had was not strong enough for me, considered the 1.5 ton, but the 137" wheelbase 4100 is the same strength as the 3800 (1 ton), the longer wheelbase 4400 would be a tad stronger, but I did not want that long a wheelbase. Decided on a 2 ton 6100 (137" wheelbase) but ended up finding a 6400 (161"), and I am glad I did, as I think I will like the about 12' bed.

For your project I would suggest you start with a frame that suits you from a bigger AD truck. 1 ton would probably be fine, and then next choice is a 4400, either original or shortened, then 2 tons come next.
I also liked the bigger fenders on the 1.5 and 2 tons as I can fit 9R22.5 tires I want to run.

Grigg

You are going to be fabricating any way you approach this.

Since you are converting to four-wheel-drive you are already dealing with the track width issues of any newer frame and front suspension, and may also be narrowing the front axle.

Ignoring those issues for the moment, either you are fabricating suspension and drivetrain mounting, or you are fabricating cab and sheetmetal mounting. Either way you are biting off a pretty big project.

I've seen a 1-ton GMC of this era with a Cummins under the hood and know of others. I'd suggest you investigate the dimensions of the 3600, 3800, and 4100 frames. Each is incrementally a little bigger and thicker and the longest of those is 137 inches wheelbase. The 4400 and 6400 have 164 inch wheelbase. Longer chassis were used under school buses.

Compare those dimensions to the modern Diesel powered pickups built for use similar to what you plan and see if that tells you if you need to swap to something newer, or just a bigger era correct truck.

I'm not advocating either approach, but rather suggesting the decision be made based on a solid understanding of the options and implications.

Personally I'm working on a number of projects including one that is a frame swap. I've revisited the logic that lead me to the swap several times and keep coming back to it being the right choice to meet my objectives on that truck.

Frame and suspension modifications are hard enough to pull off you want to be sure you know why you're doing it before you start.

Yes and no, there is no significant difference in the 3800 and 4100 frame. Best I can tell the 4100 is just longer on the front to mount the bumper differently than the 1 ton that has a different bumper and brackets.

It all depends what you are trying to do. I feel that the original frame choices are good ones, and they will be the least amount of work to use, they also look right if you care about that (I do for my truck). I considered a frame swap, and now that I am done with my frame modifications I still think I made the right decision to use the old frame. My truck will be an every day driver, taken on long trips, some really long, and regularly haul heavy things.

Grigg

Pick up some 10 gauge and box in the existing 3600 frame. A box section will be 4 times as stiff as the C-section

While boxing will increase the strength and stiffness, remember that the frame will need to flex to prevent stress cracking, especially under a heavy load or off road use. That's one of the reasons that you don't see full boxing at the rear section of 3/4 and 1 ton pickups, especially where the hitch attaches, and on over the road semi trucks. They need to flex to prevent cracking of the frame. Boxing the areas such as the steering box mount and perhaps the suspension and engine mounting areas would be wise, however.

I guess I should have looked it up before writing that. Without looking it up, I think the difference between a 3800 and 4100 frame is actually the extensions used to mount the big truck bumper instead of the little truck type.

I did look up the frame dimensions looking at the height, width and thinkness of the main rails. 3800 and 4100 are the same. 4400 and bigger Chevy trucks including 5000 and 6000 series are all the same according to my '55 1st resto pack.

There are a few threads about boxing frames, and my take is that it's asking for trouble. And or for the work involved it's not worth the actual gains and problems created.
Perhaps it's OK for a frame that was designed form the start as a boxed frame, but welding on a C-channel frame to box it without a complete understanding of welding, required frame flex, and other factors may not be such a good idea?

I did effectivly box my frame just at the rear engine/transmission mounts. Made matching C-channel pieces that bolt inside the frame, helps transfer the weight of the engine on the top flange down to the bottom flange as well, the rear front Spring mounts also bol through this piece. And the crossmember tying the frame rails together bolts to them as well.
this picture shows the two boxing pieces (one front left on trailer) and the new U shaped crossmember [IMG]http://thumb9.webshots.net/t/59/59/7/77/48/2858777480080251109QvHMaJ_th.jpg[/IMG]


Grigg

Confirmed by my 1949 Chevy truck data book for salesmen.

4400, 6400, and 5000 series frames all have identical side rail dimensions. The C- channel is 8.875" tall at the thickest part, 2.875" wide, and 1/4" material for all these trucks.
Thus they are similarly strong, some models are identical (4400 and 6400) and all models are nearly identical other than wheelbases and the cab mounting for the the 5000 series.

I thought there was a difference between 1.5 and 2 ton, I guess not (other than 4100 being essentially a 3800). looks like you could have special ordered a heavy 4100 that would have used the 6100 frame.

Grigg

Let me go into a little more depth about what I'm looking to do guys.

Engine:
I'm looking at building a hot 3.9 cummins. Twin turbos, intercooler, 4 inch exhaust, larger injectors, maybe a hot cam, full engine balance, ect. I think a 5.9 like the one in my dodge pickup is too large (and heavy) for the 3600 chevy. A 7.3 powerstroke is also too big/heavy, and a 6.6 duramax is too expensive. I also have a cousin who owns a diesel shop and loves the cummins, so parts and know-how will be in ample supply. Plus that inline sound is just mean.

Trans and t-case:
I want to put a nv4500 behind the 3.9 and then use a nv transfer case from a dodge.

Axles:
I'm not sure on what axles to use, I need to do some reading on widths and strengths. I was thinking along the lines of a Dana 60 and a Dana 44, but like I said, I haven't done much reading up on the axles yet.

Overall use of the truck:
I would like this to be a daily driver. I don't have any use for a truck that can climb a mountain, but I would like it to be able to get around the farm without any trouble. I would also like this truck to be able to pull a light(4000 lbs) trailer on occasion.

As far as the frame goes:
I don't mind if the truck looks a little different or rides a little higher, a new suspension and heavier axles will change the stance anyway.(although I would like to keep it looking close to original). I know there is probably no direct swap but I am looking for something that is strong enough to take what I want the truck to do. I can modify a frame, that isn't the problem. I'm just interested in the frame that takes the least amount of effort to work with my requirements and the body.

Thanks for the help so far guys, keep the suggestions coming!

For what you want to do I think a 1 ton is more than strong enough (my choice) and the 3/4 would be fine if off roading was mild.
The 1 ton frame is simpler because it is straight other than the drop down starting at the rear of the engine, and the narrowing starting at about the transmission, from there back it's straight and parallel. A 3/4 ton frame is funny shaped for almost the entire length, slightly harder to work with.

I am sure you have seen this site, lots of good stuff for Cummins swaps. http://www.4btswaps.com/forum/forumdisplay.php?f=2

I have heard of, and I think talked to, someone around here who did the 3.9 in a 3800. John and Peggy know who he is, and may have even seen the truck. Apparently it's a pretty simple install.

Your truck will be pretty tall with 4X4, just to get the front axle to fit under the frame and still have some suspension travel.

Grigg

Yep, 4btswaps is a good forum for the 3.9 cummins. What are the differences in dimensions between the 3600 and the 3800 frames? Or, do you know where I can look to find that?

Kyle

I'll scan what I have on the frames and send it to you this evening.
-edit- already sent

Grigg

I have to agree, the plans you describe do not sound to me like you need any more than the 1-ton frame. The axles you propose are not what you'd use for anything bigger.

I would grab the 4.5 vs the 3.9 Cummins as a starting point. Just my opinion. The Dodge FH is unique to the Dodge 6B and not shared with anything else, however the 2002 and earlier Dodge ISB FH will bolt to the back of the T2 Cons / Gen and ISB02 and older 4Bs (Frong gear train)

Grigg, regarding boxing frames, yes, you will need to know how to properly box in a frame and gusset the cross-members to prevent fatigue cracking. To me it is a simple structural engineering exercise

You don't want no little Dana 44 and 60! Get yourself some Rockwell 2 1/2's, Atlas II transfer case, and some 60" military tires. Then you can go to a tractor trailer grave yard and pick up some C channel and cross members for the frame.

Thanks for the pages grigg.

This is a website I found that has a lot of good info as well:
here

I did some looking around and I'm thinking about a dana 60 front and gm 14 bolt rear.

Was that what you were looking for on frame info?

It's tempting to go bigger and stronger, but be careful, as the big thing you add is weight, and it adds up quick, then the truck weighs so much you need even stronger stuff, and all the sudden you don't have enough engine.

Decide what you want/need the truck to do and build for that, and a tad more, but don't build a tank if that's not what you need.

You said it needs to do three things:
1, daily driver
2, get around the farm without any trouble but not climb a mountain
3, pull a light(4000 lbs) trailer on occasion.

From that information I think that you need a light truck:
1, Daily driver needs to be light to be fuel efficient
2, A 2 wheel drive with a locker will get around really good on a farm, not a mountain climber says real 4 wheel drive is not terribly important.
3, 4,000 lb is not much of a trailer.

I would go back to a shortened 1 ton frame or a 3/4 ton, Dana 60 rear, and 44 front if you must.

If you jump up to 60 and 14 bolt that's a big step in the heavy truck direction, and you will then be tempted to follow those with similarly heavy components.

Think about what you will do with the truck, and build accordingly.

Grigg

Aardvark,

I'm in the process of doing much the same thing you want to do, although I started with a '57 3800 Pickup.

I had some channel fabricated to fit inside the original frame from just behind the front crossmember to just ahead of the rear axle. I had another formed for the rear (although they made it too short, I was hoping to have it installed over the weekend).

I have a Dana 60 from a '87 K-30 for the front and a Dana 70 from a '92 P-30 van for the rear (dually axles).

I'm planning on using a Duramax/Allison combination in mine (to keep the truck all Chevy).

I'll load some of the pics to my Webshot account soon (http://community.webshots.com/user/Lane9999). (Actually uploading the pics as we speak!)

Lane

Really, what about Isuzu? Not to give you a hard time, well not much of one, just couldn't let that pass...
It's the thought that counts right?

While "brand loyalty" is something, I don't think it should come before reliability and practicality. If you are essentially building a truck from scratch It's a mistake to overlook potentially suitable parts because of who you think made them.
I am building my own truck, and I don't care who made the parts so long as they perform flawlessly and provide the simplest and cleanest solution to the problem at hand. My engine, while it says Detroit Diesel, was actually made in Brazil. My Brake Master cylinder is from a Ford, because it was the simplest to make fit a remote reservoir, motor mounts, ford again, because they worked the best of any I could find. I also have plenty of GM stuff, but only because I figure they are the best parts for each individual job.

Grigg

Yeah, I know about Isuzu. Although, it was made possible through a partnership with G.M. (Thanks Grigg!).

Pics are up under "59 Chev Frame Work".

In pic #31, you may be able to make out the axles laying on the floor behind the frame.

In pics #31 and #33, you can see where I cut a piece out of the channel and welded it back in place to fit over the triangular indentation on the original frame where the steering box mounts.

I'm planning on extending the reinforcing all the way to the rear of the frame once the new pieces are ready.

Lane

If we are talking about where things are made, it should be known that cummins blocks (at least the pre-2003 5.9) were cast in Brazil(dreaded 53 blocks ) and Mexico.

I also believe that GM bought out Isuzu's interest in Duramax Ltd. making the Duramax 100% GM, but I've been wrong before.

Which engine are you using, LB7, LLY, or LBZ? I see you have a 2003 2500, but I cant imagine you would tear apart a truck that nice, would you? If you did I guess you could always put a 6.0 Vortec back under the hood, they run pretty good for burning gasoline. I have plans for using an LB7 in another truck but I wanted to build something I could have a lot of fun with, without the electronics or automatic trans.

The frame is looking good, and this is turning out to be a pretty good discussion.

No, the '03 2500HD is my current daily driver. I work in the oil patch up here and need to get around a little. It has the 6.0l Voretc in it. I wish it had a Duramax!

There's a place up here that sells parted-out motors. I can get a Duramax out of an '05 (LLY) with 30,000 km (about 20,000 miles) on it for about $ 6,000.00. I can get an LB7 with 50,000 km for about $ 4,500.00.

Now, all I need to do is find the elusive Allison transmission!

Lane

I would definitely go with the LB7, assuming it came out of an '03 or '04. Way better engine plus it doesn't have the emissions controls the LLY must suffer. You can turn well over 800 hp with a LB7, not to mention the dyno killing torque. Those numbers make me rethink the little 3.9 all the time, but the old p7100 pump on the cummins is hard to pass up.

Lane,

I watched the slide show of your double frame job, quite a project. Looks like it will be pretty stiff...
What's the final plans for the truck?

Grigg

Grigg,

Mainly a daily driver once I retire.

I'd like to find an old Airstream trailer to fix up and tow behind it around North America.

I screwed up when I ordered the channel. I ordered 1/4" Mild Steel. I didn't realize the original frame is only about 3/16" thick. I figured once I had it, I may as well use it. I know that it'll hold up to anything I throw at it once it's finished.

Many moons ago (over 20 years ago, now that I think about it!), I worked in a truck shop preparing trucks for the oilfield and other heavy applications. I build winch trucks, installed blowers, pumps, winches, PTO's, auxilliary transmissions, truck bodies, tanks, headache racks, bumpers, etc. The memories of how to do things like I'm attempting now come flooding back. I did the same to many Kenworths, White's, Hayes, Western Stars, etc. back in the day.

Lane

All the B blocks are cast in Brazil and Mexico, been that way for many years. The B fuel pumps come from India, not sure where the turbos are made lately (although I can check when I get to the office if it really matters)

For what it is worth, a stock 3.9 with tweaked fuel pump, 6B marine damper, GM 12-bolt rear and a BW T-5 in a '54 AD pulled a 6000# horse trailer all around the US racking up about 250,000 miles while getting good fuel economy, and cruising at 70mph. Estimated 180hp (it never made it on the dyno). The trans was the weak link, however lived with proper driving

Scott

Thanks for the info Scott, good to know the old 3.9 will be able to lug just about anything I can hook behind it. What gears do you run in your 12-bolt? I was thinking along the lines of 3.55. Oh, and did you have to modify your frame much?

Kyle