Anyone on here ever swapped a ball joint front end onto a 320?

[NL320-1963]

I am thinking I want to have the better front end components and disc brakes.  Has anyone here tackled the swap?  If so, how did it turn out?

[Charlie69]

Here this guy has done it correctly.

 

https://ratsun.net/topic/34698-320-balljoint-conversion/

[Stoffregen Motorsports]

Thanks Charlie.

 

I will add that the difference between the stock 320 and the 320 with the 720 clip was remarkable. Not just the braking, but the steering was lighter and more acute, and the harshness from kingpin suspension was gone.

 

The most difficult portion of this job was the steering column. If you may recall, I retained the upper 320 column, but made it self supported with bearings and seal from the 720 donor column and by welding on a plate that bolted to the firewall. It wasn't actually difficult, but the machining and measuring time was a lot more than I expected.

 

Looking back, after all these years, I would do this swap again, but I would make cleaner frame plates or even try to hide them inside the frame.

[NL320-1963]

I liked the way that turned out.  After I get my 320 from my buddies yard to my house I will see if I can find a donor 720 frame.  I suspect that it will be much more difficult now as there are very few left on the road.  When you say frame plates, do you mean extra steel that was welded over the connection point of the two frames?

[Stoffregen Motorsports]

Yes, the term is eluding my brain right now...scab plates? Funny, because I fabricate for a living.

 

I would run them completely internal and then plug weld them to the existing frame.

 

If you read the whole thread, you may have noticed the part about the torsion bar width, well when the 720 frame was narrowed to the right width for the 320 torsion bars to work, the frame widths were about 1/4" per side off, so there was a step in the  welded joint, which is where I put the scab plates. I'm sure I could figure out a cleaner method now. And then there was the one pate on the front frame crossmember that stood out like a sore thumb. That could have been hidden completely by inserting it inside the frame.

 

I have done frame shortening before without scab plates. If you do a z-notch, when you bring the two cut frame halves together, they fit together like a puzzle with a short vertical weld joint, followed by a long horizontal joint, and then finished with another vertical weld joint at the opposite end from the other vertical joint. This way is supposedly the strongest method of joining structural steel without and scab plates, But precise measuring, scribing and cutting are required to get it done right.