AD frame swap question

[Azraelx13]

Has anyone ever swapped an AD onto a C30 chassis? I have the front half of a 53 Chevy 1700 - Canuck equivalent of a 2 tonne i think, but she needs a frame. I also happen to have a 78 C30 drw hanging about as well. Any info you guys might have would be greatly appreciated

[dsraven]

haven't seen one but, having swapped a 57 onto an envoy, I have some experience with frame swaps. first do a track width coparison to see if the wheels from the newer frame will tuck into the fenders of the old cab without rubbing. especially if you want the truck to be lower than the old style, more like the "78 was. keeping in mind that the '78 likely had a smaller diameter set of tires on the front you may make it. will you be using duallies on the rear or a single wheel configuration? doing this to have an actual hauler or a lowered hotrod?
you will also need to figure out these items as well as the track width

-the obvious one here is the cab mounts. you will likely be best served to keep the cab/fenders/rad support etc from the old truck all bolted together and place it over the new frame so you can get an idea of how the ride height will be and what will need to be lopped off the newer chassis. start with the frame blocked and sitting level or at the rake angle (front to rear angle) that it would normally sit at with the rough weight of the cab sitting on it. then try to get the front wheels centred in the wheel openings as you and some friends lower the cab and clip down until it bottoms on the frame somewhere. try to find a frame drawing on the net or contact the gm heritage centre for a drawing with dimensions for the frame. they are great people to work with and get back to you pretty quick. the other option is to buy an assembly manual for the old truck which will probably have the drawing in it as well as how things go together and get adjusted to open/close properly (hood especially). you can try the link here to see what you find. look at several years of your body style because the notes are different each year ot seems
http://chevy.oldcarmanualproject.com...esto/index.htm

-will you use the stock cab mounts or the rubber mounts from the newer chassis

-I would suggest to take good measurements with pics of them so later you have a reference when the truck is dissassembled. snap pics of how everything comes apart because these projects have a way of spanning a few years to complete (trust me) and by that time you have forgotten which panel overlaps the other or what the pieces actually look like, as a quick example

-steering column from old to new. old truck was narrower here so it won't line up with the newer style box for width plus the newer chassis has a strg box mounted further forward so you would need to add some shaft length and some bearings inline to keep things moving properly without binding. you may also find the shaft may have exhaust manifold clearance issues with a v8

-firewall and floor may need to be modified to fit over engine/trans in newer chassis. I suggest to cross brace the cab with the doors on and fitting so they close well etc just so things stay in shape when the project is moving around and gets set down on the newer chassis. then mark each hinge well or drill 1/8 holes in the door/hinge bolt up area so the doors will go back in the same place. a pin can be placed into the drilled holes later for line up purposes. if you have an engine hoist you can fab up a quick cab lifter to lift the cab through the door openings so you can slowly lower the cab onto the chassis and hold it at any height while you block or fab mounts. that is how I managed to do my swap safely with only one guy in the shop-me-and no back injury or bandaids

-how to hang a set of pedals under the dash so they are secure. also power brake unit on firewall will likely require firewall support to handle the added stress of the push from pedal set

-if using a standard trans will need to come up with a set of pedals that will do the job plus assemble some sort of linkage. I would suggest a hydraulic clutch set up from a newer truck. there are aftermarket set ups with clutch slave cylinder in the bellhousing. not sure on price though

-track width and tire to body clearance with suspension fully bottomed and steering turned all the way, body mounts, firewall and floor clearance, steering column and linkage, pedals and brake unit (look at hydroboost to keep things smaller dimensionally), clutch and/or auto shift mechanism (could look at steering column from newer vehicle with column shift but cable operated linkage, like astro van? but they would have auto o/d trans so extra detents for extra gear), radiator and hoses, wiring, licensing and inspection, new vin to denote "assembled vehicle" and be the proper number of digits (Insurance Bureau of Canada) so you are covered if you have an accident. wouldn't want to find out too late that your insurance is going to "bow out" of coverage because the vehicle they insured has been modified but not disclosed to them. you would probably need some sort of roadworthy inspection as well. like anything else over 10 yrs old in Alberta.
I talked with the insurance Bureau of Canada representative responsible for this area and he said he would need to see a bill of sale for each vehicle, in your name, and also keep the vin tag from each vehicle (if the tag is removed from the cab for some reason, like sandblasting in my case) and he will take the old tags and issue a new vin for the unit and attach it to the cab. also it will be named "assembled vehicle) to denote that is was assembled from various units.
have fun but check into it first so you don't spend time and money for nothing.

pm me if you want to chat about other stuff on frame swaps

[Azraelx13]

Thanks for the info. Figured this would be one of those try it and see. Got my leg work to do now. If it works out tho going to be a nice rig.

Cab mounts will need to fabbed up either way, And floor replaced. Going to take a cue from Lower50s build - mine is pretty much the chevy counterpart.

Good to know about registering it in Alberta. I know my current provider probably won't touch t with a 10ft pole.

[Flysocal]

Wow dsraven that's a comprehensive response full of useful info. Wealth of knowledge on this site.

[dsraven]

what do you want to end up with in the end? a old style commercial truck on a new chassis? that is, a 1 ton cab and chassis with a deck or commercial box? do you want a conventional truck with a regular truck box behind it? a long (like 9 ft) box like some old 1 tons had?

if you plan on a commercial box behind the cab there are options available at truck outfitters for an "army" look box.very practical but not that appealing to the eye of most custom guys. google rebco for their version. check out the coe collection here for some ideas of what guys have done for something behind their cab
http://67-72chevytrucks.com/vboard/s...d.php?t=162216

if you plan on having a pick up box behind the cab, not a deck, then plan on a short sided bed, inside, because the newer style trucks have a kick up behind the cab so either the cab has to raise up to match the box height or the box has to be "cut down" inside to match the lower cab height. if you plan on having a deck, like a farm truck or a car hauler, then it wouldn't matter so much.
you may have to cut the frame and shorten it if you plan on a normal truck box, unless you fab up something to your likingback there and attach some truck style fenders to it. that would mean a driveshaft refit as well. also check the frame width and compare to a box to see if a regular truck box will fit on the (I assume) wider frame of the newer style trucks. the old truck has a tapered frame that was narrower in the front. if memory serves me. there is also the 9ft box option.

check the front wheel centerline dimension from the firewall on the old truck and compare to see roughly where the cab will need to sit in comparison to the engine on the newer style frame. the hood and fenders on the 1.5-2 ton trucks were a bit longer I think so you may have some extra clearance there for a rad and fan, if the cab has to sit too far forward.

anyway, just some thoughts. post up a few pics of what you have to work with and you may get more results

[Azraelx13]

If it fits on the c30, the plan is to do it up like a small semi. The box is somewhat flexible, and part if me is thinking of running a bare frame. Main goal at the very moment is get it sitting on a frame and driveable. It's most likely going to be in rough shape body wise for several years.

Going to get some measurements this weekend. And probably start a build thread too. Luckily i do have the original frame from the cab forward. Thanks again for the tips etc.

Flysocal, couldn't agree more. Partly why I have been lurking for the past year and researching.

[dsraven]

ok, grab a coffee,

before you start with the frame mock up make sure to check the donor frame for true. get it up on stands, level it up front to rear and side to side. I have a set of stands modified for this purpose. the adjustable part has been removed and replaced with some large threaded rod that sits on some rectangular tubing tacked onto the top of the jack stand. the tubing is drilled so the rod wil fit through it and then there are lock nuts to snug up to keep the rodding at whatever height I need. the other end of the rod has a 3/8 bolt welded to the end and the bolt goes through a hole in the frame of the truck with the same lock nut idea used there as well. there is usually a hole already in the frame, matching on each side, or you could drill one to accept the bolt. then it is easy to get the frame levelled up and it will stay exactly where you dial it in when you are working on it. that way you don't have to worry so much about bumping the frame, as you move stuff around and work, getting it off level. less time spent checking after each bump. a periodic recheck is advised though. very handy for doing a project like this one where you need to keep things level so they all line up the same. a rake angle can be worked into the mix as well for someone who is installing an IFS or a different suspension clip. that way things get done properly not just by eye.note that the stands used in these pics are not the ones I talked about earlier. this was a simple mock up and the frame was checked and found level at this point just sitting on the stands as seen. a couple of small shims were all that was needed here. sorry, hypocryte talking, haha.

I would also recommend a digital level before you get too deep into it. it is a great investment of under $50 and you get way better results than a bubble level because it doesn't rely on the angle you look at the bubble. it is what it is, read from any angle. they usually also have magnets and a built in laser as a bonus and are backlit so it is easy to see from a distance. a shorter style level is cheaper and could simply be placed on a longer piece of metal (like your 4 ft level like I used) or even a straight piece of wood you have kicking around as long as it is dimensionally the same throughout th length and straight.

then, after the frame is on stands and level, mark your cross members at their midpoint between the rails of the frame. I usually just use some masking tape for this but you could also center punch a mark on each one for future refernce if the frame is dirty or greasy. mark each one clearly so you know exactly where the middle is between the rails of the frame. then use a stringline or a laser and go from the middle of the rear crossmember to the middle of the front crossmember. the string or laser should be hitting the center mark on all the crossmembers in between. if not then you have some work ahead of you to get it straight. after that do a corner to corner measurement, with some help hopefully, and those numbers should be the same or within 1/8 of an inch. this can prove to be tricky if your helper doesn't hold the tape measure the same on both sides and try to use a tape that is graduated the same on both edges, so not a metric and standard tape or one that only has markings on one edge. that way your results won't be skewed by pulling the tape out of actual alignment so you can read the graduations on the other edge of the rule. you could also use something that doesn't stretch, like a piece of dog chain or a length of wire, and then mark and compare the reults. that way you know it will be held the same on each measurement. a magnet, c clamp or vice grip can be used as a substitute for a buddy, and drinks less beer, haha.

once the frame is found to be all good and before you start placing the cab, you may want to get a dimensional drawing of the original frame so you know the difference in height between the cab mounts, or floor of the cab front and rear, and the rad support height. that way you will know roughly what you will need for shim packs at the different locations on the new frame for your mount mock ups. it will help you get the cab and the rad support in the correct plane so the front clip aligns nicely with the cab and it doesn't look like the cab is sitting on the frame at an angle.

you will need a couple of lengths of 2x4, 4x4 or something else to span the width of the frame so you have a solid and stable base for the cab to sit on initially. you could wire that in place so it doesn'tmove around or fall off at a critical time. also, an assortment of wood blocks of different thicknesses kept handy to use as shims under the various body parts as you level it up. some pieces of plywood in different thicknesses also helps to use as shims as you progress from simply getting the cab on the frame to actually levelling it. in the end, for final levelling, some large flat washers work good for thinner shim packs to get everything levelled up. when the initial mock up is complete you could cut some hard wood or stack up some plywood to the right length for the mock body mount height so you can stand back and admire or you can have it sitting on a better base if the fab work for body mounts is not going to be done right away. soft wood can be used but may crush easily, if you are getting in and out of the cab while working, skewing the level. stacked plywood pieces work well and are hard to crush. if you have a hole saw you can easily pre-make a whack of them, in different thicknesses, to be all the same when stacked so they would be easy to work with. if you think about where to put the shims in relation to where the new body mounts will be placed you can leave them in place until everything is mocked up, with the front clip on and level etc, then simply fab up some body mount stands, with the right space left for mount pads, so the cab sits where you want it.then the shims canbe removed after the new mounts are bolted up. don't forget to allow for mount "squish" when the bolts are tightened down.

you will need some wheels and tires, of the correct size for your finished project, so you can see the tires in the fender wheel openings because sometimes the fit can look different depending on how low you have the truck over the wheels. in the attached pics you can see the tires in the openings at roughly the original 57 front wheel center point. with the truck lowered down to my desired ride height. you can see they look like they are stuffed into the rear of the opening. I have marked a point at the centre of the wheel opening and it looks good to my eye, at that point, at my desired ride height. it is about 1 1/4 to 1 1/2" ahead of the original axle centerline in my case. it is a personal choice thing.

finally, once you get the frame all level and straight, you may need to seperate the clip for cab placement (like I did because my help also has a job in the daytime and my front clip was also predamaged from an accident so I have donor fenders, hood and rad support), but if you mark the mounting areas, take some pics for reference, then dissassemble as a unit if possible, you should be able to get it back together the same or close. if you have an engine lift you can fab up a simple cab lifter to do the fitting easily by yourself. I have attached a pic of my 57 going onto an 04 envoy frame. I did that by myself with the engine hoist "buddy" and no bandaids.

when it comes time to fab up some body perches I find square tubing works well because it is easy to work with, is flat on every side so a mount can sit flat on top of any side, it can be cut back on the sides that don't need to be there, it can be cut and bend easily in a vice for flanges at 90 degrees to the main part and has a more factory look when done. my opinion though.


anyway, hopefully this helped you or somebody.

post up a few pics of your project so we can see what you have to work with. a pic is worth a thousand words.

a little forward thinking helps keep the bandaid box full at the end of the day.

[dsraven]

below is a pic of the frame stands made from jack stands. they can quickly be turned back into jack stands by simply grinding the tack welds off the square tube that is attached to the top of the stand. it is sitting pretty high at this point so less reliable reading due to the rod angles not quite vertical. when installing the front end I had the frame much closer to the ground. the rod was about 2" above the stand. more reliable and sturdy. the pic also shows the digital level on top of the 4 ft level. the bubble level looks good but buy the digital version it would show the frame ouit of level by a couple of degrees. if you are good with that then go with the bubble level. if you like to be dead on then go digital. fron end alignment guys are usually digital.....just saying.

[Azraelx13]

Looks like quite the setup! And a nice clean shop to boot, little envious. I will definitely keep all you have said in mind when the time comes. It sounds like you have had a fair amount of experience doing swaps, 57 your only one?



This is basically what i started with. Initial plans were an s10 swap, but the frame I got has a section rusted through where the web and flange meet, right under the original rear left cab mount.


Did a quick mockup on the s10 (before the crack was found) and realized i would need to run bigger wheels in the front to make it look decent. Or just rework the fender to something completely custom.

The C30 just popped into my head a few weeks ago and i started wondering why not try that. It fits more with where i want to take it, and it already has the v8, or could hold up to a diesel if I decide to go that route. I will also admit some laziness/ignorance, as i did some research many years ago on dropping the 53 onto the c30 (before i was pulling wrenches to put beer on the table) and came across something about the frame being too wide. Looking back it was probably track width, and I honestly didn't know the 1700 was a 2 ton.

I just realized I forgot to grab a coffee before i read your post...

[dsraven]

haha, your loss on the coffee.just like the old time high school tests, read the first line first, haha
if the front clip is still intact as a unit try to get a measurement off it for track width to check the c30. or you could try the oldcarmanualsproject for some gm drawings of the body width. it looks like the box is still kicking around as well, by the pics, if that is your place in the pics.
the s10 would have been ok but you would have wanted a different front clip on it after the fact. better off anyway.
the shop is nowhere near that clean at this moment.

[Azraelx13]

Got the coffee this time. And you are correct, that is a box from the same generation. Just not the same truck. From what I was able to get from my gramps, he picked up the 53 for the rear end (was a 2 speed) - ended up using if for some random project. The rear end behind the 53 was acquired somewhere along the line, Not sure the history on it. The c30 is actually his as well, was his dd for years when I was a kid. The front clip is still burried past the rails, so I can grab measurements from it. Everything is sitting out at my dad's empire of dirt, so nice easy access!

It's always amazing how fast a shop can go from spotless to epic disaster.