Here are some Powermatic 66 documents/publication reprints and threads that I assembled in a meta-analysis of various threads on owwm.org and vintagemachinery.org.
Motor Frame Sizes
I have a PM66 with a "Frame 56C motor" although people have talked about other frame sizes in their PM65/PM66. Basically you have to spend some time with your saw, measure the motor that's in there, and compare overall dimensions since an extra long motor may hit the cabinet. I found the following tools really helpful:
Castellano Motors Frame Spec ToolGrainger NEMA Motor Chart
vintagemachinery.org publication reprints & Photos
This is the date of publication, the title, and the number in parentheses is the number of pages in the document (e.g. "(18)").
Sorted-by-Size Powermatic Table Saw Entries on VM's
Photo Index03/18/2016 Table Saws Measured Drawing For PM 66 Motor Cover
(1)
http://www.vintagemachinery.org/pubs/detail.aspx?id=15006
1983 (May) Table Saws 66 Tilt-Arbor Saw-Operating Instructions
(18)
http://www.vintagemachinery.org/pubs/detail.aspx?id=6140
1983 (Nov) Table Saws 66 Tilt-Arbor Saw-Maintenance & Parts
(24)
http://www.vintagemachinery.org/pubs/detail.aspx?id=6139
Unknown Table Saws Model 66 10" Tilting Arbor Saw
(24)
http://www.vintagemachinery.org/pubs/detail.aspx?id=4327
June 2001 Table Saws 10" Tilting Arbor Saw Model 66
(28)
http://www.vintagemachinery.org/pubs/detail.aspx?id=3327
Unknown Table Saws Model 66 10" Tilting Arbor Saw
(23)
http://www.vintagemachinery.org/pubs/detail.aspx?id=1280owwm.org threads
The number in parentheses (e.g. "(28)") denotes how many total posts there are in the reply. Also included in the topic title, date started, and original author. Please feel free to add to this list, but note that they are in reverse chronological order (newest first).
New (to me) 1987 Powermatic 66 (PM66) - Vibration Issue
(41) by themrbruceguy » Thu Jan 13, 2022 9:37 am
https://owwm.org/viewtopic.php?f=1&t=230881Powermatic 66 lock knob shaft...anyone have a measured drawing?
(10) by uhoo33 » Mon Nov 14, 2016 1:06 pm
http://owwm.org./viewtopic.php?f=1&t=177206PM66 crank handle assembly: face plant
(28) by 9watts » Fri Jun 24, 2016 7:08 am
http://owwm.org/viewtopic.php?f=1&t=173194
Restoring Powermatic 66, update May 8, 2016 - Painted
(36) by kenbw » Thu Mar 31, 2016 6:08 pm
http://owwm.org/viewtopic.php?f=1&t=170890
PM66 arbor bearing,advice needed
(11) postby normandie » Fri May 06, 2016 3:13 pm
http://owwm.org/viewtopic.php?f=1&t=171962
PM66 - arbor locknut
(24) Postby KirkTr » Sat Apr 16, 2016 8:55 am
http://owwm.org/viewtopic.php?f=1&t=171317
Powermatic 66
(31) Postby nashley » Mon Jan 18, 2016 10:39 am
http://owwm.org/viewtopic.php?f=1&t=168468
Powermatic 66 history
(17) Postby cbdeajr » Wed Nov 04, 2015 6:23 pm
http://owwm.org/viewtopic.php?f=1&t=166411
pm66 I just bought, I have a unisaw, which should I keep
(22) Postby sniper695 » Fri Sep 25, 2015 4:20 am
http://owwm.org/viewtopic.php?f=1&t=165209
PM66 Arbor issues?
(21) Postby ztifpatrick » Fri Aug 28, 2015 9:10 am
http://owwm.org/viewtopic.php?f=1&t=164234
Marty's Powermatic Model 66 Restoration
(86) Postby purdue417 » Thu Aug 27, 2015 3:47 pm
http://owwm.org/viewtopic.php?f=1&t=164217
1977 Powermatic 66
(26) Postby Rickinnocal » Sat Apr 25, 2015 8:02 pm
http://owwm.org/viewtopic.php?f=1&t=160587
Did I break my PM66 motor?
(23) Postby Brad Swearingen » Wed May 20, 2015 6:16 pm
http://owwm.org/viewtopic.php?f=1&t=161405
1968 Powermatic 66 Table Saw
(82) Postby Matt3357 » Mon Mar 09, 2015 6:06 pm
http://owwm.org/viewtopic.php?f=1&t=159002
Question on adding Wide Cast Iron table to 1997 Powermatic 66
(11) Postby Dave in Indy » Mon Aug 18, 2014 11:06 am
http://owwm.org/viewtopic.php?f=1&t=151985
Powermatic 66 Table Saw motor pulley
(14) Postby rudy1337 » Wed Jul 02, 2014 12:34 pm
http://owwm.org/viewtopic.php?f=1&t=150473
PM66 restore/new member
(57) Postby maxhall1023 » Fri Apr 04, 2014 5:55 am
http://owwm.org/viewtopic.php?f=1&t=147269
PM66 dust collection (or lack thereof)
(6) Postby kevincnc » Fri Dec 13, 2013 12:02 pm
http://owwm.org/viewtopic.php?f=1&t=141042
My New-To-Me Powermatic 66
(85) Postby greenmachineman7 » Mon Sep 23, 2013 2:53 am
http://owwm.org/viewtopic.php?f=1&t=137891
1967 Powermatic 66 Disassembly
(34) Postby berdman » Sun Sep 15, 2013 7:27 pm
http://owwm.org/viewtopic.php?f=1&t=137582
Yet Another PM66 Restoration
(81) Postby bdemore » Thu Aug 08, 2013 7:18 am
http://owwm.org/viewtopic.php?f=1&t=135922
Powermatic 66 needs a little attention
(119) Postby Shop Dad » Fri May 31, 2013 8:15 pm
http://owwm.org/viewtopic.php?f=1&t=133346
1985 Powermatic 66 completed 5/19-new pics
(28) Postby JeffHeath » Mon Apr 22, 2013 4:18 pm
http://owwm.org/viewtopic.php?f=1&t=131834
Powermatic 66 Arbor Quandry
(80) Postby jrhutty » Wed Apr 03, 2013 4:52 am
http://owwm.org/viewtopic.php?f=1&t=130909
1989 Powermatic 66 with Excalibur Sliding Table
(23) Postby BenMartin » Wed Jan 23, 2013 8:23 pm
http://owwm.org/viewtopic.php?f=1&t=127370
Powermatic 66 Arbor assembly
(14) Postby okieblue » Mon Nov 05, 2012 6:32 am
http://owwm.org/viewtopic.php?f=1&t=123637
Table insert for Powermatic 65 & 66; the same?
(3) Postby nytstyk » Mon Mar 05, 2012 6:43 pm
http://owwm.org/viewtopic.php?f=1&t=111873
Moving a Powermatic 66?
(13) Postby tolken4 » Thu Jan 19, 2012 7:37 am
http://owwm.org/viewtopic.php?f=1&t=109121
Powermatic 66 w/ rack and pinion fence
(4) Postby Craftsman » Tue Jan 17, 2012 8:34 am
http://owwm.org/viewtopic.php?f=1&t=109012