No. Polyurethane tanks are not available as a replacement. There were some that went inside the old fiberglass (wingtanks.com) but I think that venture died with its parent, Airdale. The tanks are structural to the wing and polyurethane doesn't offer the needed strength. The new tanks from Kitfox are of a more ethanol resistant fiberglass. I put these in my rebuild and have been very pleased with them. I had the creamed tanks in my old plane and never had any issue, but watched them closely.
As I said, when I spoke directly to Robbie, I asked him how large he can make the spring, width and height, to fit a Kitfox Model IV. This is what I now have. Avid fuselage attachments are not the same as the Kitfox IV.
Avid gear won't fly on a Kitfox, because it won't fit. Nothing to do with pissy...
The larger gear for the 5-7ss won't work on a 4. Neither will an Avid Spring. They are 5" wide, where the Kitfox IV is 4". What I had them do for me is the largest possible, still fitting the properly engineered mounts for that airframe. Been there, done that.
That is the standard Grove gear and it works great. I had that on my previous Kitfox IV-1050. I used the Grove 6 x 6" wheels and double puck brakes because I HATED the Matco brakes on the bungee gear. I didn't like the look of the wide Nanco/Nanking/King Fox ATV tires and wanted to go to a more durable aircraft tire. I settled on 21 x 800-6 Aero Classic tires from Desser. They were affordable, durable and plenty big for my needs. To do this conversion, I already had the parts from my project plane so I cannibalized them as a learning experience to see if I would do the same on the new plane I was building. It worked out very well. I chose to do the slightly longer spring on the Mangy for more ground clearance and a better 3-point angle of attack after talking with Robbie Grove. Since I was building the plane at the time I reinforced the side longeron truss to strengthen this area in anticipation of the longer gear legs and possible future Bushwheel tires. The investment to do the complete Grove system is substantial. Wheels, brakes, gear and tires will set you back $3500 or more. From my experience, this was money well spent in the performance gains I experienced. Some may not agree with this, but I have been very happy and do not regret spending the money.
If it's really from '92 it could be a 3 with the 4 upgrade, making it a 4-1050. This was offered to the orders placed for a 3 when the 4 came out. I have a friend (JimS) who took this option when he ordered his kit.
When I got my new tanks from Kitfox, I rinsed them with ascetone then with E85 garbage fuel. I used about a gallon of each PER TANK. I collected the waste rince and inspected it for any forign matter or discoloration.
It's possible there is an HID version, but the ones Leni and I have are LED. To expand, my installation is hampered by the placement of the light fixture being more aft on the wing chord than optimum, decreasing the beam efficiency. If I were able to surface mount the lights, they may work better as a landing light. My lights: Link