Technical parallell leaf to hairpin conversion

After driving my Essex with a horrible break bump steer ( with added loss of caster when breaking), I'm thinking about a conversion to hairpins, or maybe even four link front axle on my current build, a 1930 Marquette two door sedan.
I would be thankful for any suggestions on how to do this kind of modification. I want to make a safe conversion, and would appreciate pics or links on how to do this.
Alternatively I could use an aftermarket Ford front axle, of course. This would probably be more costly, and not as fun, it's nice to have home made parts, provided it's safe and looks okay.
My rod will be fendered,that's why I would consider a four link setup, as it wouldn't be visible anyway.

 

I know there are many rods with each of these front ends, if properly set up they can work well. If you are having issues under braking conditions then I would check the shocks, the alignment etc. But properly setup 4 link and hairpin suspensions work also.

 

We did this with a Dodge, we used a Model A front crossmember and installed it just like the car was a Model A or 32 Ford, HRP

 

That's what I done on my Plymouth, model A CM and hair pins. I hate the look of the 4 links myself.

 

You may have created a lot of the bump steer by mounting the steering box low and having the drag link at a pretty steep angle. That is fighting the angle of the back half of the leaf spring.
Secondly, what is up with the second drag link on the passenger side?

 

Sorry @Mr48chev to leave this hang for over a year.
Yes, you're right, the angle of the draglink is not ideal, which would have given some bump steer in any case, but the worse problem on this setup was that the front axle, with its paralell leaf springs, would roll forward when braking, so that all caster was lost, and probably even worse. AND on top of that the steering arm would be pulled back from the axle roll, to steer the car sharply to the right. Not fun.
The "drag link" on the right hand side is connected rigidly to the front axle to keep it from doing the roll when brake was applied. Sadly, I made it too weak, so it bent, and destroyed the caster totally, so I removed it. Later I decided that I want to build another rod with, hopefully, some lessons learned. The Essex was sold some six years ago.

This graphic explains why the drag link-looking caster bar had an idler arm in the back.

 

Modern (1950's) front leafs had the shackle on the front of the spring. If you do that and mount the steering box where the drag link will be close to the back of the spring mount, your bump steer will be minimized.
As to the braking changing the caster, a half leaf on the rear half of the spring will minimize spring wrap without sacrificing ride.

 

The front spring with just a minimum number of leaves left isn't helping anything. That is where your spring wrap when braking is coming from. The reverse of spring wrap and wheel hop on a rear axle on acceleration. I have just about the same issues with my 48 Chev pickup with all too many leaves removed. When you hit the brakes you had better be ready to keep the rig under control. That and you have to ride herd on it all the time just like you say you have to do with yours.

The distance between the center of the pitman arm and the pivot point for the spring isn't helping bump steer either.

If you are still thinking about going to a Ford style cross leaf setup I'd first measure the width of the frame at the axle line to see how close a Model A style crossmember fits between the rails.
This link shows the aftermarket crossmember that a lot of guys use or they use a copy of this one. Down in the left hand corner is one that is a bit wider. Lowered 1928 - 1932 Ford Front Crossmember (roadstersupply.com)