wrong bolt on timing cover?
http://www.hastingsmfg.com/Service%20Tips/ford_truck_piston_scuffing_broke.htm

Thermostats for 330, 361. A little more than halfway down the following link. Maybe "open" and "closed" refers to whether there's positive crankcase ventilation (PCV).
http://www.gates.com/catalogs/fleet/FordThermo.pdf

remanufactured engines (including origibal 330 or 361 and more recent 460):
http://www.remanufactured.com/Ford_8_Cylinder_Engines.htm

cheaper remanufactured engines from Joliet,Illinois:
http://www.motoresremanufacturados.com/ford8.html
No idea why website is in Spanish.

and more expensive:
http://www.bestrebuiltengines.com/FORD8.htm

lots of data on part numbers,casting numbers, dates, etc.:
http://www3.sk.sympatico.ca/harrism/shopmanual/group_01/Identification.html

This was in the middle of a long email exchange not worth wading through:
***text follows***
Date: Thu, 10 May 2001 13:31:26 -0500
From: Landen Schooler
Subject: Re: 68 Ford 600 Roll Back - Questions

A 390 will fit fine if you install the front timing cover
off of a 330 medium
duty on it..It fits the mounting bolts etc. I have done it
twice since the
361 and 391 engines had cracked heads and I could buy a
running 390 for about
1/4 the cost of the parts to rebuild that 361..

Cecil in OKla.


But you won't have the forged crank and rods...

Landen Schooler
Palmyra, Iowa
***end of text***

By Gordon on Monday, May 27, 2002 - 10:34 am:

FT Series Engines
Ford Truck series blocks, 330/331/361/389/391, are similar to FE's, but with beefier parts. The blocks are heavier, with beefed up main bearing webs. The cranks were typically forged steel, and will interchange with FE's if you use the FT timing chain cover, damper, and pulley. Or you can have the thicker 1.750" snout turned down to 1.375", the standard FE size.

The above lifted from
http://www.fordmuscle.com/archives/2000/04/projectfe/index2.shtml