Front End Issue

[SCFFR]

I recently completed my MkIV roadster but have run into an issue with the LF wheel. While the body was in the paint shop, I took the go kart and had the front end aligned (used the specs in the FFR manual). When I reinstalled the body, I discovered that the left front tire rubbed the body when the wheels were turned (around the 10 o'clock position if looking at the tire from the side). I also noticed that the LF tire was more forward in the wheel opening than the other side. The RF tire had plenty of clearance and was centered in the wheel opening.

I rechecked all of the front end pieces. I verified that the FFR tubular lower control arms were in the right bracket holes (lower outboard holes), the UCA were in the proper location and the spindle adapters were correctly installed (I'm using 1995 spindles).

I put a post on the Factory Five forum and got several responses. I replaced the new 245/60-15 Cooper Cobra tires with a pair of 235/60-15 Cooper Cobra tires. This got me about an additional 1/4" clearance. I also worked the wheel opening lip and removed a portion of that.

The majority of the posts suggested that the alignment was wrong so I measured the two UCA's and discovered the LH appeared to have different arm lengths (smaller) than the right one. So, I adjusted the arms on the problem, left side to be the same length as the right side knowing I had messed up the alignment.
This morning I took the car back to the alignment shop and explained the problem. I had hoped that the clearance problem could be fixed with the caster angle. Before he started on the front end, he centered the front wheels and measured the distance from the front to rear hubs on both sides. The right side is 3/4" shorter than the left which explains why the left side tire is more forward in the wheel opening. He then measured the caster and found the right side to be 3 degrees (positive) which is what he had set it in the go kart stage. The left side was 5 degrees (positive) which meant adjusting the caster for more clearance was out of the question.

His suggestion was to either move the holes in the frame brackets (where the LCA's attach) or have the LCA modified to shorten the rear tube. This would move the bottom of the spindle rearward so the tire would be centered in the wheel opening to match the right side.

The only positive thing is that the car drives perfectly straight. The is no shimmy or shake and absolutely no tendency to pull either left or right. The mechanic even commented as we pushed the car over his shop floor that it rolled perfectly straight.

I asked if he should adjust the right side caster to match the 5 degree setting on the left side and he said that since it was steering fine with no issues to leave it as is.

Any suggestions as to why the wheelbase would be off 3/4" from side to side? We centered the rear end and with the non-adjustable arms on the 3-link system, I would think the rear end is pretty much fixed in place. Also, the rear tires are perfectly centered in the wheel openings. I know the FFR tubular LCA's are welded in a jig but is there any way the one I have on the left side could be defective?

Just wanted to mention that the mechanic is highly experienced with 50+ years of running his own shop and racing multiple dirt track, circle track, modified and drag cars. If you are having a problem with any type of front end/alignment, he is the guy to see so I think his credentials are solid.

Thanks,

Ron