Have you called the seller? They should replace the odd caliper. Those calipers have two different style pistons and seals. I went through the different seals issue before
. Do a search in "brakes" for "rebuilds".
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1970 T1 W/MassIVe 2913cc RAT/?EFI? w/direct fire (very soon) and 915 trans
1962 SC 1776cc SP 944NA brakes, 993 wheels
VKG