Hi, I have been trying to put the vented discs and ATE calipers from a 164 onto a 1972 142s. I have ended up with a very low, soft, and spongy pedal. Any ideas?
I have bled the system several times according to the manual using a power bleeder and still no luck.

Check the front calipers and see how many bleaders they have 1 or 4.If they have more that 1 per caliper make sure you bled from all of them.Some times they will act like that if they arent bled from all the bleaders.You can also try to bleed the master cylinder as well the make sure there is no air there either.