Trikebent's 40/46 Project
 

Well I did it. I bought a project.
Cab is a 1940 3/4 ton by the tag (KE) Front Sheet metal is 42-46. Rear fenders are 5 bolt (fender to sides) Real solid cab, 1/2 ton bed that's in pretty good shape Front sheet metal looks pretty solid as well. The grill is almost perfect. Truck has an updated rear end (GM style with a 10 bolt cover) and a independent front suspension partially installed. I don't know what it is yet, It has a Manual rack and pinion. Wheels are 5 lug Chevy S 10 I think 5 on 4 3/4"
Nothing is bolted to the frame at this point.
First step is to bolt the cab down at the stock height and see how well I can get everything to fit. I read that the 40 cab is 2" shorter, so I want to see if it all fits.
I also need to see what the wheelbase is as it sits

Re: Trikebent's 40/46 Project
 

looks like a factory mustang II suspension, from an actual 74-78 mustang II.

the 40 cab is the same as 41-46, even the windshield and gauges interchange.

looks like an outstanding start

Re: Trikebent's 40/46 Project
 

sounds like you'll have some sorting out to do with all the mix matching but congrats on the truck. A lot of good guys on this site to help, I'll be looking forward to the build

Re: Trikebent's 40/46 Project
 

What is the stock spacing between the cab and frame? I want to temporarily bolt down the cab in the stock height. Then I can comfortably re- attach the front sheet metal

Re: Trikebent's 40/46 Project
 

chevys of the 40's sells a kit wth the all the proper blocking, rubber pads, and springs. Probably better off getting the kit instead of screwing around making your own spacers.

Re: Trikebent's 40/46 Project
 

The clean up begins.
I imagine I could learn a lot about the history of the bed by analyzing the stuff that came out of the rear stake pockets.
Both back pockets are rusted thru about 2-3" up from the bottom, but not bad considering.
Normal mouse nest above the windshield. Need to remove the Wiper motor covers to get at that.
Removed the pass door latch, Its broke and needed some creative screwdriver manipulation to open the door, glass is gone so I could reach down and lever open the latch.
Inside of the door was about 3"-4" deep in nest/dirt/glass and the link between the inside door handle and the latch. Bottom screws that hold the inside door skin on are rusted tight. I gently pulled back the inside panel and vacuumed down to get PB on the reluctant door screws.
What everyone favorite method of removing rusty stuck screws. Current plan is PB blaster, screw driver then (gently) hammer driver then drill if that fails.

Re: Trikebent's 40/46 Project
 

the very best tip I have for rusty clutch head screws is to use a cutoff wheel in a grinder and carve a slot right in the center of the screw. you can get good enough at it that you dont hurt the panel, and then take a flat screwdriver to it while its still hot, I have never had one stay stuck after that.

Re: Trikebent's 40/46 Project
 

Looking hard at putting this on an S10 frame. If I did, do I need to worry about the 'bulge' in the S10 frame behind the front wheel?

Re: Trikebent's 40/46 Project
 

yes, you will need to trim the frame to clear the body and running boards.

you already have a suspension upgrade, its going to be way less work to use what you have.

Re: Trikebent's 40/46 Project
 

I always liked seeing guys building with original frames, but thats just my preference. Two totally different kind of builds

Re: Trikebent's 40/46 Project
 

I am an original frame guy also. Putting a mustang 2 front on the original frame is a pretty simple deal and looks good when done.

Re: Trikebent's 40/46 Project
 

his second pictures shows a MII already installed. shortbed, 1/2 ton, good rear fenders, vin plate, trikebent doesnt need a lottery ticket this week because he already won.

Re: Trikebent's 40/46 Project
 

An oem mustII/pinto front crossmember is not a good thing to have with out additional reinforcement. By the time you do all the additional things that will be required you might as well install a aftermarket crossmember that was designed for the truck. It will work better and drive better.

Re: Trikebent's 40/46 Project
 

after looking at the pics again I wouldn't trust that front install around my yard much less on the road at 70mph

Re: Trikebent's 40/46 Project
 

I'm leery of the workmanship on the M II frontend. I'll do a through I inspection of the welds and alignment before deciding what to do.
Thanks for the feedback. Looking at other projects on line, I am realizing I have a good start foundation to work with.
I've been side tracked by needing to replace both rear wheel bearings on my daughter's 4runner.

Re: Trikebent's 40/46 Project
 

even if you need to do what CSHADES says, buy a new crossmember and weld it in, you already have 80% of what you need. I would stick till I found a compelling reason not to.

I use an S10 chassis when the modifications needed for the factory frame are too great, like sometimes I will buy a grain truck that has been cut in half because the cab is in good shape, or I will have a complete truck but its a 3/4 ton that will need shortened, that kind of stuff. not everyone comes up with a nice 1/2 ton chassis right off the bat.

Re: Trikebent's 40/46 Project
 

As of now I'll stay with the stock frame.
Took a look at the rear axel. Its a 76-79 GM 10 bolt based on the number stamped on the housing. Its a posi, 3.08 ratio by the numbers. Score! I'll keep it

Re: Trikebent's 40/46 Project
 

Found this in the glovebox

Re: Trikebent's 40/46 Project
 

Love the phone number on the scraper! I think it has been there for a while. LOL

Re: Trikebent's 40/46 Project
 

My son actually stared digging the glove box and found it. He started to dive in to the pile of dirt & mouse droppings without gloves or a mask. I have to stop him and have him get PPE on. No telling what was in there!
Also found 3 bulbs, the missing pass side wiper arm, 3 pedal covers, Oly beer label, and a usable dash knob, and a cork lined bottle cap. fun stuff.

Re: Trikebent's 40/46 Project
 

neat stuff! I just found squirrel poop and once I even found more squirrel poop.

Re: Trikebent's 40/46 Project
 

Found a donor truck for the small bits I'm missing.
Cab is real rough, lots of rust thru. Looks like I'll have a spare set of interior door panels, inner fenders, possibly both front fenders and a complete hood. Windshield frame looks to be toast. It's painted like a Navy truck. Plastic on the door handles. No bed at all

Re: Trikebent's 40/46 Project
 

if its a navy truck, make sure its not a big truck, the fenders look close but arent.

my 41 is a military truck, I would swear it is a 42 but the cowl tag is a 41 so thats what its titled as.

Re: Trikebent's 40/46 Project
 

I can tell the 1 1/2 ton and larger fenders. How do you tell the bigtruck from the 1/2 & 3/4 ton fenders? Wheel opening size?
Navy truck is marked 3/4 ton on the doors. The plate on the cowl is not readable at the moment. I need to carefully sand it an see if I can read the stamping.
It has glass in the doors. My project does not. The donor has a frame around the glass. Is that standard or a military thing?

Re: Trikebent's 40/46 Project
 

there are many different front fenders, 1/2 ton to 1 ton, optional 3/4 ton and 1 ton, 1 1/2 ton and 1 1/2 ton high cut.

look at the running board, the larger fenders (used on some 3/4 and 1 tons) will have a standard wheel opening but will drop 3-4 inches further down in the front and rear. compare it to your first truck, it will be apparent if its different. There is a guy on here that had a set of the bigger fenders on his truck, he didnt know till he bolted them up!

the cowl plates on the war years were steel, not aluminum like the early and later trucks. if you think the number is there under the rust, get some evaporust from cardboard freight, it removes the rust and leaves all the paint. mine was a mess, after soaking a couple days I got the number and could even see the original silkscreen painting on the plate.

40-46 had metal frames around the window, the 38-39 did not and according to jim carter the glass would rattle in the doors and break. so its the right glass for you! installing them is a snap, literally, in fact if you havent pulled the door panels your original glass may just be at the bottom of the door.

Re: Trikebent's 40/46 Project
 

The stock steering wheel/box were removed by the PO. I'll be using a Mustang II non power front end/steering. I'd like to use a stock steering wheel and possible a van column without the ignition switch. What does it take to mount a 40-46 wheel on a column like that?

Re: Trikebent's 40/46 Project
 

quite a bit actually. the 46 was the last year that mounted with a woodruff key. in 47 they switched to the splines that they used all the way through the 2000s. so if you had a 47 wheel, it would bolt right on the van column. the way it is though you would need to add the splines. if it were me I would probably use a hole saw and cut the steel center out of later wheel keeping the spines and the horn pass through intact, then cut the center of the 46 wheel, and have someone with a tig welder weld them together for me.

but it doesnt end there, the early wheels dont fit the van column in diameter either, so you would need to add a cosmetic piece to cover the gap. its not impossible, some guys have done it on the 47-53 side of things. I really prefer the 41-46 three spoke to the 47-53 three spoke so I would try to keep it too.

Re: Trikebent's 40/46 Project
 

OK update time.
I have leaned what the differences are between a 40 and 41 cab. I have a 40 cab and I believe the rest is 41-46.
40 cab has:
No Clutchhead screws
Bolt in back window
Front fenders do not bolt to cab sides
Firewall is 1.5 inches closer to the back of the cab
The removable floor pan is 1.5" shorter as well
Windows do not have a frame around the glass

To marry a 40 cab to 41-46 front sheet metal I need to:
Extend the firewall to Core support brace by 1.5"
Extend the inner fender 1.5: back to the firewall
Drill Inner fender mounting holes in the firewalls
Drill matching holes in side of cab to bolt fender to cab
Mount the rear hood latch 1.5" forward of the current firewall or extend the latch rod 1.5" back.

Re: Trikebent's 40/46 Project
 

Found THE way to remove stubborn screws. I have a old air powered Dayton 1/2 drive impact wrench. I also have a Craftsman 'Hammer style' impact driver. The Craftsman has an adapter from 1/2 drive to hex. That adapter fits the Dayton and lets me use the Dayton on stuck screws. A quick tap with the impact and the screws give up and turn or in rare case break the head off. It worked like a champ on the door hinge screws.

Re: Trikebent's 40/46 Project
 

actually the 41 still had a bolt in rear window. I have had different 40 cabs with clutch head screws and with out. The frames are also different 39-40 to 41-46 by an inch and a half of length.

Re: Trikebent's 40/46 Project
 

I pretty sure I have a 41-46 frame. Wheelbase is 115"
I had everything bolted down, cab, bed & core support. With an extension in the firewall to core support, Hood/grill/ fender & running boards all fit pretty well. The inner fenders did not come all the way to the firewall. I had a 39-40 frame, I don't think I could get the hood/fenders to fit?

Re: Trikebent's 40/46 Project
 

Engine & trans roughed in. Engine is an 89 5.7 Chevy w/ TPI, 700R4 trans. I have the TPI computer & stock wiring harness. Winter project is to cleanup the harness.

Re: Trikebent's 40/46 Project
 

sounds like you have a 41-46 frame from what you are describing

Re: Trikebent's 40/46 Project
 

Aren't mustang front suspensions 5 on 4.5" wheels. The front driver wheel looks like a cutlas wheel, maybe not. Is it running adapters to 4.75?

Re: Trikebent's 40/46 Project
 

Original mustII/pinto wheels are actually 4 bolt. You can run a 1973-77 chevelle front rotor with the Mustang II bearings and races and an aftermarket bracket for 78-88 monte carlo calipers. You can also install Granada front rotors for the ford pattern

Re: Trikebent's 40/46 Project
 

I need to measure the pattern on the front hubs. There are no adapters.
The plan was to use Granada Rotors with the GM pattern, but maybe someone has already swapped in the Chevelle rotors

Re: Trikebent's 40/46 Project
 

those are cutlass rally wheels in your first picture, should be 5 on 4.75. remember when you measure a 5 lug pattern its center to EDGE, not center to center.

https://content.speedwaymotors.com/A...6f0a33769e.jpg

Re: Trikebent's 40/46 Project
 

OK, I have GM 5 on 4.75 on both front & rear. Lucky again:)
Does the Chevelle rotor use the Stock Mustang bearings? If not I hope the PN are still on the bearings.

Re: Trikebent's 40/46 Project
 

Use the mustang II bearings and RACES, Use the chevelle seal. There isn't enough room for the washer, nut and tin lock nut unless you can find a washer/nut combo. I usually don't use the washer and haven't had any problems.

Re: Trikebent's 40/46 Project
 

Great!
I was planning on Granada rotors & GM 'metric' calipers. I didn't know about the Chevelle option.
Currently beating on sheetmetal right now. Using a HF hammer & dolly set to work out the kinks in the front fenders. Very happy with the results so far. Using a borrowed MIG welder to repair the cracks. Plan is to have it all ready to sand & prime by spring. getting too cold to paint now.