I now have a 300ex with 400ex suspension front and rear,well I had to use a 250r rear shock because it gave more clearance room on the upper mount.I must say it is a 200% improvement for minium costs,I have appox.$450 into the project with my buddy and I doing it ourselves out into the garage and making our own mounts for the front shock tower and rear shock linkage to the frame.
We did this to see if we could make it work and work right.I'm passing this info on for anyone wanting more room and better suspension on their 300ex.

2- 400ex
1- 300ex
1- xr80r

 

do u know how much wider it makes it on both sides? thanks

 

The 400ex is like a inch wider and the rear is the same as the 400ex,as well as the wheel base...

 

I think it is 2 inches wider on each side.

 

Hey DAD400EX,

Can you send me some pics of your 300EX with the 400ex susp or a website where I can see what the finished product looks like??????

 

I have a few pics of that 300ex ,I'll have to email them to you,but I sold the quad as far that goes.