Rubber or poly bushings in the front? 3/16" TOTAL or 3/16" each side?

3/16" total (3/32" each side) is acceptable with rubber bushings. You could get by with less with poly bushings. 3/16" each side is a little more than I'd like with either type of bushing.

However, your post references "feeling" like you have the same toe as before -- how are you actually measuring toe-in? There's no substitute for getting it on a machine or a toe set with jackstands, a carefully set parallel (to the rear wheels) string and careful measurements.

I run stiffer poly bushings on my 240. I shoot for 1.5mm toe-in each side - which is a little less than 1/16". I'd go 2-3mm with rubber bushings.

Having said all that - I wouldn't expect that shimmy would be a symptom of a mis-set toe. It might pull, exhibit odd turn-in traits or wear the tires funny. Shimmy usually means something that should be tight isn't -- ball joints, bushes, etc.