Personally I would have the speedo on the left also. It does balance the chassis better there. It's probably only part of the problem though.
So, the first thing I would check is the axle heights. Double check that the camber is the same on both sides and pull the tires off. With the chassis flat on a set-up board measure the axle height on both sides with calipers or a sedan droop gage. The axles should be the same height within about .25mm and if they're not try loosening the screws on the lower arms and giving them a little jiggle before retightening. I've had the lowers get a little off after hitting a wall or from just getting assembled a little funny. If you can't get the axles correct try new screws in the lowers and you might need to replace them all together.
Second thing is to check the caster. Just use a camber gage at the front to measure how the kingpin leans back. Again, wheels off, chassis flat on the board and make shure that the upper pivot sets flat on the gage. I try to keep the caster within a half degree for both sides. Contrary to some of the agruments on here it's not that hard to reshim the upper arm to get them the same. If you need a little more room to move just dremel a little off the block to make room and add a shim. It's not a big deal.
Also, check the springs. A factory driver told me to set-up new springs like this. Compress the new springs some with your fingers (just enough to gently bottom them out). Put them on the car and shim them at the spring end to take out play or add one shim of preload if you're running 18's. Run the car once or twice and recheck the springs for proper shims (no preload for 20's and one shim for 18's). If one of the springs collapses from where you set them (crash) you'll need to start this process over again.