wrote:
A friend and I have rebuilt a stinson 105 HW-75 .We are looking for an
stc to put an 0-320 in.I have heard there was one for an 0-290D
somewhere but I've been unable to find it anywhere.Any help would be
appreciated

There are Stinson Clubs on Yahoo that could be helpful:

http://groups.yahoo.com/group/Stinson
718 Members, Archives: Membership required
Welcome to the Stinson Aircraft Forum If you're looking for a "free"
access, public forum to exchange information about the 108 series of
STINSON aircraft - this is the place. Please visit our Database folder
where you can post items wanted or for sale as well as recommended
fly-in destonations. Looking for technical assistance? Post a message...
there's a lot of experience right at your fingertips. Don't forget to
check out our photo album and links and Remember - flying a Stinson is
flying ...(more)
-
http://groups.yahoo.com/group/StinsonMarketplace
StinsonMarketplace
99 Members, Archives: Membership required
STINSON MARKETPLACE : Dedicated to everyone who loves Stinsons that have
no other outlet for selling parts or airplanes. Group is open to anyone
and discussion of any Stinson subject. Feel free to post your own ads,
let the rest of us know about what is going on in the Stinson community.
Thanks, Guy Hamilton N2721L.

There are installations upto 0-435's in the L-5 series (Military 105).
http://barnstormers.com/listing.php?...r=mattwolf1213

Go he
http://www.airweb.faa.gov/Regulatory...e?OpenFrameSet
Then click on BY MAKE and the following:
Consolidated Vultee Aircraft Corporation, Stinson Division
Or just type STINSON into the SEARCH window. I saw STC's for unspecified
ENGINE MOUNTs, RESTRICTED CATEGORY listings, as well as some for
specific engines such as 0-235, but not the 320 series. I can't imagine
a 4 seat plane with 75 hp...