Limp noodle 29 Model A cab-reinforce to chop for extended cab??

Not sure exactly how to approach this. Yeah, I'm subscribed to threads about chopping the top. No problem there. However, the 1929 Model AA truck I bought didn't come with much of the original wood that held the cab together. I apologize in advance...this'll be a long post...

I get new wood body blocks and have shimmed up the cowl to get the doors aligned where I need them. But now that it's coming down to the point where I have to do this myself, I'm having some questions. Perhaps I should explain...

Here's the plan. I hear all the complaints about how much room there ISN'T in these cabs, even when unchopped. Solution?-Extend the cab. Once you extend the cab and have a good seating postion, you pretty much look left and see nothing but steel. Solution? Put in windows (I have a pair of 30-31 Fordor rear windows I'll graft in with a chop to match and fit the extended cab area behind the "B" pillar). OK, I can sit and see now, right?

Now on to the actual questions.
1) You can see from the pics there isn't much wood left. I bought some new "B" pillar (door post) wood (but would like to do them in steel). I understand I have to tack in some steel tubing, etc. to firm up the body and measure crossways for square. But, once I go to put on the extra cab corners, how should I handle that part AND extend the subframe to incorporate the new addition and still keep the cab square?

2) In pic 2, I put the new door post wood just for a check fit and you can see the gap near the bottom of the seat platform. I see where a bolt needs to go, but once I weld in the bracing and go to do the chop, I don't want to sacrifice the wood piece, but need something to give me reference for cab shape since I can't really tell how the bottom of the sheet metal relates or attaches to the subframe. Right now, I'm just depending on the current sheet metal shape as reference. I guess maybe I'm overthinking this, but since I'm a dangerous hobbyist hack with a cut off tool and a mig welder who is building his first hot rod, I'd like to start off with as much of an advantage as I can without making more problems for myself that I have to fix later.

3) Pic 3 is just a stupid picture of when I bought this project. It was a "greenhouse" at some kiddy park in Denver...

Thanks, guys...
Chris

 

Build a jig, and put the cab on it.

 

Thanks, Gimpy. Short and sweet. I guess most of the chops I followed had been done on the frame. I figured I had to get everything aligned, straight, braced, etc. before messing with anything else.

So, you're saying the bottom line is to pull the cab, build a jig, drop it on, do the deed, reinstall the cab and mess with the door alignment and fine tuning later? It sounds easier as I'd be working on the ground and all. I just wanted to make sure I didn't end up with a lopsided cab that leans to the left or whatever when I dropped it back on the frame .

 

They way that I have done it involves cutting 2x4's to fit inside the subrails and screwing the subrails to the wood. You want the cab base dead-flat, and well supported. If you cut the 2x4's longer than stock, by the amount you want to stretch, you can cut about the last 4" off the subrails, where they go parallel, slide all that back on the wood, and then make filler panels to make up the gap.

This was a mangled, rusty '29AA, being channeled 4", but it shows the very back of the subrail, where you want to extend.

 

There is no need to remove the cab from the subrails. This one was rusty enough to remove itself.

 

Keep us posted on your progress.

 

Oh, and brace the cab some before pulling, such as you can brace a noodle.

 

Cool! Good info, Gimpy. Thanks. The pix you posted make a lot more sense now and I like the idea of moving the subframe back and filling in the middle. I think the subframe on this one might be better than the AA you described.
I may also be channeling the cab, but that'll be after I figure this part out...As you know, that AA is a 6" frame and I don't want a 6" channel after a chop, you know?

Timberbeast: I'll keep ya' posted, but I move really, really, slow. 1 divorce, 3 moves, and a couple of surgeries have prolonged this project, but I think I'm somewhat on the road to moving on this thing now.

 

If you are careful when placing the engine and trans, you don't need to stretch it. A stock firewall and narrow seat back and its pretty comfortable. The phone booth tall cab is what makes these trucks look so neat.

 

Yeah, a 6" channel would not leave you a happy driver. I parted out my 157" dually AA, and built a new frame, using A rails for the exposed part, 2x4 tube for the rest. It is on its way to being a radical kustom, as it was way too far gone to do much else, and I am just that way. The nose is my avatar picture.