Where to slice, That is the question!

I haven't started my build thread yet, but I do have a technical question before I touch the cab on my 38 Diamond T. I know that there is plenty of opinion on the forums here about extending or not extending a pickup cab. I have pretty much decided it's the only way we will be comfortable in the cab for what I hope is a lot of travel. I also respect how much ability or the lack thereof I might have to do this but I guess I will learn by doing. I plan on cutting and extending from behind the door post back either 6 or 8 inches. I do not want to cut the door, cowl, etc. as has been suggested to others on the forum many times. I'm looking at merely cutting the sides barely behind the posts, straight up to the roof line and jogging forward about 2-3 inches (because that is where the roof is not crowned in looking across). The cab on this truck has a point where the wedge from the front stops and goes straight back, if only for a couple inches. The doors even have a curve toward the back where it seems to flatten out right before the door post. I have placed some tape on the line where I'm planning on making my cuts. My question after such a long explanation is: am I heading in the right direction or do I need to reset? Thanks to any and all advice.

 

I guess you get all the cutting options mentioned due to keeping the cab proportioned.
I’ve seen some not so nice to look at extended cabs
I’d make a slice where the best chance of hammer and dollying the welds are
That’s probably as good a choice as any

 

To keep the proportions the same I would go through the center of the doors. It may be more work but it will look better with no chance for blind spots. But your way could work too.

 

that's probably the easiest way to do it on that cab.

Have you done some photoshop work, so you can show us what it'll look like when it's done?

 

I did blow up that picture and do an outline drawing and then expand it to see what it would look like. It reminds me of the much older semi cabs like White and Autocar with a short sleeper on them.

 

Most of the time when extending the cab on these old trucks, I think a builder is better off if they can acquire a second cab. That allows them to cut the second one slightly longer than what they cut off the first one and mate them together. It also provides doors to help extend the door length with just one vertical weld. Usually, when extending the cab on an old truck, if its all done behind the door, the proportions look "off" somewhat. I'm not talking about those where people try to emulate the "extended cab" look and maybe even install a small window in the side corner.....just talking about trying to get a little more room inside.

On the Rio, the cab proportions (IMHO) are wrong to begin with. It's very thin behind the door right from the git-go.
It may be that simply extending your cab will actually improve the proportions. I would try moving just the rear section back as you have proposed and add a couple of thin brackets to support and adjust its location temporarily.
Go to Costco if you can and you will find that they have the perfect cardboard for making patterns....and its free. In the section where they keep the toilet paper, they have these sheets of cardboard between the packs of toilet paper. I stick a few of them in the bottom of my cart and tell them at the register. They always say "no problem". Use the cardboard to fill the gap and put a little red primer on it to simulate the trucks color. Then stand back and see if you like how it looks. Ask your friends opinions too. Take your time deciding............ Its kind of similar to the old measure twice, cut once scenario. Don't rule out extending the doors till you look multiple times at how it looks with stock doors. Good Luck with your Rio, I always kinda liked them and think you'll have a unique ride when done.

 

Having driven many old trucks, my experience tells me that if you extend that cab back 8" to 10" from the point you have the front edge of the vertical tape, and you slide your seat back into that area (the purpose of extending the cab), you are creating a huge blind spot on both sides of the truck.

Your head will end up being completely behind the "new" side of the truck and you won't be able to see anything on either side of the truck without leaning way forward. Your field of side vision will end at the back edge of the door window. The rear facing window in the cab won't help with your side vision. If a car is on either side of you but behind the door window, you won't be able to see it at all. If you come up on a stop sign on a road at anything less then a 90 degree angle to the road you are crossing, you will not be able to see anything at all on the that cross road on the sharper angle side. You may not even be able to lean far enough forward to see anything.

You can test this pretty easily if you can sit in the cab currently. Simply put a sheet of paper how ever long the section you are adding to the cab length to the back side of the door window covering the door window (if your adding 8" of cab, add 8" of paper on the rear part of the door window). Put the paper over the back end of both door windows. Then sit with your seat back against the back of the cab. What ever side view that piece of paper is blocking, the extra length of the cab will also block. Have someone stand, or place an object at the farthest rear point you can see on each side. Then mark or have someone stand at the farthest forward point you can see looking through the back window of the cab towards both sides. Everything between those two points on each side are blind spots in real life. If you need to get out of the cab and view size of the blind spots from outside of the cab, do it!

Then tell me how much will you will enjoy driving the truck without being able to see that much area to either side of you?

Now you can see why guys are putting windows in those cab side extensions. If you consider adding a side window, that could change where you might want to cut the sides of the cab.

The other option may be exploring a shorter steering column, repositioned seat (higher, lower, more upright), different seat, or modified floor, to gain more space. Old truck cabs are just smaller then modern truck cabs.

 

Post a Request on the photoshop thread asking for views with the dimensions you're considering to see what it will look like before doing any cutting, they will be happy to help.
https://www.jalopyjournal.com/forum...-to-end-all-photoshop-threads.300531/page-955

 

One other thing to consider is just lengthening the door . Yes the cab has to be lengthened as well, but its a straight cut across the roof. This is where a second cab comes in handy but can be done without one. Here is a picture of a Chevy that was done that way. I think it looks good. Just food for thought.

compared to a stock one below




THIMK......first

 

@StreetKruzer
Maybe this will give you some idea of how it might look.....

 

Thanks themoose! Is it stretched in this pic? I can't tell a difference other than the tape gone. I think I have to go at least 4" to get a difference in comfort. I already tried with the seat in, problem is coming back with the firewall enough for a 6.0 ls really jams into the floor area, and I'm 6'.

 

I think a second cab is out of the question and I don't think my skill set lends itself to me doing doors, etc. I've only seen maybe five pics total on the internet of a 38 Diamond T model 201. That's what drew me to this one, not many around. That and I have some pics of my dad driving some old D T's even though this is a pickup and not the reg Diamond T semi from back then.

 

Yes it is..Here's an image if showing where the tape was on the original picture

 

I don't see where you added 6 to 8 inches to it?

 

I'm thinking about 1"?

 

Isn’t the LS shorter than the original straight six? Why would it eat real estate in the cab? I’m not understanding. Maybe we need more views of the truck and engine placement to firewall.

 

A lot of times the cab placement is dependent on the wheel opening position in the front fender.
The motor placement in the chassis is a lot of times dependent on the chassis suspension and crossmember placement.
We don't know what the fenders look like, nor do we know which suspension or where the crossmember location is, so we can't determine where the engine has to be placed on the chassis.

Its very likely the OEM 6 cylinder was centered over the front axle and that axle isn't far from the firewall, but that too is speculation. I saw a nicely redone 2 ton Diamond T in real life, once 30 years ago, don't remember many details. There is a picture of a 1947 Diamond T 1 ton pickup on the this months page on my calendar, but it is a front 3/4 view, so that doesn't really help much either.

 

When I purchased the truck in Pa, the 6.0 w/4L80e was already mounted in the frame. Problem was the PO left absolutely no room for a radiator, the water pump center stuck out even with the back of the grill shell. I moved the engine back a good 5 inches or so, which placed the rear u-joint into the center of the stock X-frame which is open from the sides. Otherwise there would be no way to get to U-joint without major surgery or opening the floor from the top to repair. Since I plan on towing a small gooseneck camper I'm also building, I wanted to retain the 4L80e instead of a 4L60e. My water pump snout is now approx 1" or so back from the radiator fan. I have a 3 row aluminum 32 Ford radiator with fan that fits great in the shell going forward from the back edge of the shell and I can space the condenser in front about an inch and still clear the ribs of the grill where they come back on the sides. And that, gents, is why I needed to cut the firewall. Believe me I wish I could have gotten around it. The looks of the cab extended will not bother me as I think it looks a little stubby behind the doors anyway. It's just figuring out where and how. For the purists, I'm sinning anyway as the truck will be much lower and have a different attitude than stock. Sorry.

 

Don't worry about the purists. Make it like YOU want it.

 

I agree!
By all means, the truck needs to be built the way OP wants it. Screw the critics, they can build their own truck what ever way they want it.

Sorry Moose, but by the looks of the two pictures squirrel posted, it looks to me like only about 1/2 the width of the tape was added to the length of the cab. If the tape is 2" wide, the original cab extended about 5" behind the door, a 5" extension should have at least doubled the original length. The OP was asking for a 6" - 8" extension. I used the trusty pointed end of a ball point pen to measure the distance between the back of the cab and the back edge of the door as a measuring stick for all the photos, and assumed the tape is 2" wide. The OP has the advantage of actually measuring the original distance between the back of the door and the back of the cab, then adding however much he want to extend the cab. I'm betting what is now 5" to 6" is going to be 14" to 15" with that 8" extension.
That is going to change the look of the cab pretty dramatically, and is going to make my 1st post here important.

 

is there any way to make the hood longer? and move the cab back on the frame?

 

Moving the cab back is also moving the wedge shape back from where the fenders align with the cab. There is significant wedge to the hood front to back also. I'm trying to wrap my mind about how many things that would change. I do appreciate all the thought people are putting into this. Thanks

 

Purist?
Seems way to late to worry about that

 

Went back looking at some pics I took when bringing this thing home, hoping I could show some relation of the original PO engine placement. Still not real good, but in the pics the crank pulley is out over the front crossmember and it is a car, not truck offset. All of the other accessories are truck. The back of the motor is maybe 1/2" off of the firewall.

 

I spent the last hr or so looking at Scotty 449's wild build on I believe a model 411 Diamond T big truck where he made a double cab. I think it was a forty something. There is a pic in the thread of a side view that shows the strip between the two doors. Anyway, for reference I think he has 10 inches spacing between the doors. I think I'm only looking at extending mine the amount of the sheet metal strip that he put in. Imagine the front cab stopping where his second window starts.

 

Here's the @scotty449 build thread:
https://www.jalopyjournal.com/forum/threads/1941-diamond-t-double-cab-build.427398/

 

There are two ads on Facebook that might be of interest to you. One is a 1935 Diamond T 306 in Greencastle In . Looks like a parts vehicle . and there is a guy in Zion Il that has some Truck door skins for sale. Says $250. www.pavleticmetalshaping.com If you did decide to extend the doors any, maybe he could make them in a longer length.

 

Just saw the same ads in facebook myself! Thanks. I'm not sure if the big truck cabs are the same as the pick up.

 

Rot & Kustom just did some photo shop for me. Boy are you guys great. I'm thinking the 4" gets the most room without chopping anything else. I'll have to see how the comfort is when I put mock it up after the cut. What do you guys think? That's 2", 4", and 6'.