TR4 - 6 Front Suspension Bushings

Are there any differences in the upper front suspension bushings for a TR4
all the way through to a TR6?
(Excluding the real early TR4s that had zero castor angle . .those may be
different)

The look like the same parts (pivot and arms) to me . .but I thought I'd
double check with all the rest of you Triumph people.

TIA

Scott Tilton
1963 TR4 Everyday