My first attempt at making equadistant headers:

First I used a metal flange as a template to mark on a strip of wood where the cylinders 

are.

Then I used a whole saw bit to cut 8 round chunks out of a thick piece of plywood.

Then I bolted four of them to the center of the cylinder marks on the strip of wood.

Next I joined a 2 x 2 to the small strip of wood, allowing for the distance from my 

number 8 cykinder to the firewall and the distance out from the motor for the frame and 

steering.

Then I made a small plywood ‘collector’ from another piece of plywood and glued the 

other four round chunks to the ‘collector’. I now had two stable points to work between.

Then I bought two 10’ x 1 1/2” electrical conduit pipes because the outside diameter 

matches the headers I have.

Next, I drew a line on the conduit from end to end. That became my centerline.

Using that line, I cut the conduit into 1” pieces, some straight and some cut at a 15 

degree angle on one end. This gave me a 3” radius.

Then I drilled both ends twice, back and front, with a very small bit.

Then, starting with number 5 cylinder, I connected each piece by bending a small piece 

of 12 gauge metal wire into a staple shape and placing them in the holes.  4 staples/piece

Since number 5 cylinder travels farthest, I ran it as straight as possible to the collector, preset at what I determined to be a good angle.

With number 5 cylinder in place, I knew the rest had to hold the same amount of pieces. ( Some straight pieces are 2" or 3")

(Oops, too many photos - sorry)

Initially I covered them with green tape but it wasn’t enough to take the strain so I

used rubber bands to hold the wire ‘staples’ in place.

Number 5 cylinder took 23 pieces when made as short as it could be between the ‘flange’ 

and ‘collector’.  I then knew that the other cylinders had to match 23 pieces.

I don’t know if this is a ridiculous or brilliant idea but I was just curious to see if I 

could create equal length headers and I have the time so why not try ?

Now I can disconnect the long segments and place them on steel mandrels, draw the angles and cut accordingly.

I guess I have to learn to Tig weld now - but I've been watching videos so maybe I'll try that too.

The total cost was about $12 for the conduit & $5 for the wire.  The wood was scrap.  This should save me wasting metal later.