Mock up the mufflers with blocking, jack stands, etc.  Then build to and from them.  You can use carboard or heavy paper to mock up the pipe if you wrap it around the pipe and tape it, and then pull it back off.  The bends are going to be trickier, but using wire for either the outside or inside radius has worked for me.  When in doubt cut long and recut.  Much easier than trying to add material back. 

In this hobby (in most honestly) I think there's no money better spent than trying to learn something new.

Nothing ventured, nothing gained. You can do it Bobby!

RTM wrote:

. I keep thinking I can just cut slices and slowly bend it inwards and weld up the slices.  But I think it would look like crap.

 
That's why God made grinders !

When doing my exhaust the last time I ran into a guy(Randy) that  said..."we close on Saturday, bring it by and we can put it on the lift and take a good look."
He/we invested a few hours and several sticks of 2 1/2" pipe and bent/welded up my whole system !
(Cost me a 50 dollar gift card to Texas Roadhouse,,he wouldn't take any $$$)
Granted...there aren't many Randys out there any more butt......it might be worth exploring that option. Couple hundred in CASH and maybe working on a holiday or weekend??!? Who-nose......
A lift and bending machine and welder and stands to hold stuff in place are invaluable compared to flat-on-your-back home garage work.
Jus say'in
Look at muffler placement too. Mine are closer to the rear axle than the engine like some installs.
6sally6

Greg B wrote:

Since you asked...this is the best tool hack out there.

https://www.reddit.com/r/AutomotiveLearning/comments/10oosst/exhaust_pipe_expander_that_actually_works/?rdt=34737


I could show you how well this works, but this video is accurate.    I originally bought the Vevor expanders off Amazon, but when I got them I did not like them.  Sent them back and bought the Lisles at twice the price and am not sorry.   

Other thing you want is the pipe pliers from northern tool.   They are made to line things up and good till you can get your welds started. 

https://www.amazon.com/Monster-Master-Welding-Release-ATHUS-MM-WLP-S9/dp/B089T1M26S/ref=asc_df_B089T1M26S?mcid=f15aedeb3ac53a99aa71a43d74099994&tag=hyprod-20&linkCode=df0&hvadid=693554822535&hvpos=&hvnetw=g&hvrand=11388349510629202743&hvpone=&hvptwo=&hvqmt=&hvdev=t&hvdvcmdl=&hvlocint=&hvlocphy=9022835&hvtargid=pla-947244419518&psc=1

And ps.  That hydraulic cutter tool from hf is an amazing tool.   There are a lot of others uses for that.    I originally bought it to work on my convertible, so there is that!  (To cut really nice die cut holes for my door wires.

 
I have a portable hydraulic ram kit but it needs all new seals.  I can't even recall what's inside the case.   Think I used it once many many years ago.

6sally6 wrote:

RTM wrote:

. I keep thinking I can just cut slices and slowly bend it inwards and weld up the slices. But I think it would look like crap.

 
That's why God made grinders !

When doing my exhaust the last time I ran into a guy(Randy) that said..."we close on Saturday, bring it by and we can put it on the lift and take a good look."
He/we invested a few hours and several sticks of 2 1/2" pipe and bent/welded up my whole system !
(Cost me a 50 dollar gift card to Texas Roadhouse,,he wouldn't take any $$$)
Granted...there aren't many Randys out there any more butt......it might be worth exploring that option. Couple hundred in CASH and maybe working on a holiday or weekend??!? Who-nose......
A lift and bending machine and welder and stands to hold stuff in place are invaluable compared to flat-on-your-back home garage work.
Jus say'in
Look at muffler placement too. Mine are closer to the rear axle than the engine like some installs.
6sally6

Sal - I agree, one should ask around for a muffler shop that does 'custom' work on cars likes ours.

Also, regarding that manual pipe expander that is mentioned in early part of GregB's video post.  I tried one years ago with the some results the video had mentioned, never thought to adapt a hydraulic pump to it. 
 

RTM wrote:

The extension pipe is bent downward because it hits the cross member brace. The collectors are above the bottom of the frame rail meaning they don't hang below the frame rail.

It looks like you might fab an extension pipe that comes straight back at the same, or only slightly lower, than the header flange, and also migrates to toward the transmission to pass under the trans support cross member as it sweeps up.  This is how mine works but with HIPO mannys instead of headers.  That gets the intermediate pipes nearer or slightly into the DS tunnel where they can be as high as possible.

Bullet Bob wrote:

RTM wrote:

The extension pipe is bent downward because it hits the cross member brace. The collectors are above the bottom of the frame rail meaning they don't hang below the frame rail.

It looks like you might fab an extension pipe that comes straight back at the same, or only slightly lower, than the header flange, and also migrates to toward the transmission to pass under the trans support cross member as it sweeps up.  This is how mine works but with HIPO mannys instead of headers.  That gets the intermediate pipes nearer or slightly into the DS tunnel where they can be as high as possible.

 
The extension is to long now but I couldn't find make small pie cuts to bend it inward.  Not sure this will look that great.  Last night I spent some time trying to place the pipes in positions to get a better idea of how I can cut the pipes for the best fit and look.  I won't be able to start the transition upwards until I pass the transmission brace.  Then I have to turn up and get above the convertible seat pan that bolts both sides together.  If it works out well you shouldn't see any pipes hanging below the car.  Maybe a little from the header to where it'll pass the transmission crossmember

6sally6 wrote:

A little inspiration ! All this pipe on a flathead Ford engine. Why cool look !!!!
6sally6

Very strange looking....   can you send a photo of the vehicle?

Here's an Internet image of a 1928 A model showing 4 spark plugs but only three exhaust header pipes.  This matches what I thought I saw in your photo...  3 pipes on each side.  Strange.  Have you ever seen a flat head engine with 3 pipes on each side?
 

TKOPerformance wrote:

They're all like that IME.  A dated design, that by today's standards doesn't make much power, but there's just something inherently awesome about a flattie. 

DITTO !

  (Rufus.....you just told us your age !!!

Their design was the two center cylinders shared an exhaust port.
A lotta sick cylinders did the same thing with intake ports.
The flat head Ford has a very unique exhaust note and maybe this is why.?.
The shared exhaust ports AND the 'big-time' looong stroke crank AND the primitive flat head no OHV combustion chamber all make a contribution to the sound.
Lotsa 'old guys' remember the sound from when they were a teenager or a kid and it makes them feel...
'gushy' inside.
(Like when I hear a stutter'in-snot slang'n-eye burning-rumpity-rump mechanical roller cammed FE Ford motor snort'in thru a set of OPEN 180 degree full-length exhaust headerz !!!)   Oh Baby !!!
6sally6

Academically I now the airflow through that engine is TERRIBLE, greatly limiting its power potential, BUT @#$% does it look sexy!