Topic: WTB 3/8-16 X 1¼ Grade 5 Ford hex cap fastener marked F

[Dan Case]

Wanted to buy.  There seems to have been two versions of one 1960s Ford fastener in Grade 5 for certain FE engine exhaust manifold attachment. See picture below. The fully threaded version is not very rare and there is an excellent reproduction of it available. I am looking for some mint used or new old stock ones as shown in the lower images with the small logo F and the partially threaded shank.

Thanks for looking.

[Dan Case]

Still hunting.

[jwc66k]

Got a Ford part number?
Jim

[Dan Case]

Got a Ford part number?
Jim

20428-S78 is how it is listed in the May 16, 1965 Shelby American service parts list.

In my hunting I have found a cross reference to a Ford Motor Company aerospace part 20428S2 and General Motors aerospace part 181114, with an indication that more than one fastener company made a part for the application, Aerospace identification NSN 5305-00-018-1114, where NSN = NATO Stock Number for all countries in NATO and the US Defense Department. And no, none of that has helped so far.

The only "small letter" bolts I have found were in collections of parts left behind after the modification or "restoration" of an original Cobra. We found a few assembly line take homes (a.k.a. lunch pail parts) of the "large letter" screw circa 2018 in Michigan and they got used in Cobra restorations. AMK Products offers copies of the large letter part.

The small lettered part is the prize I seek and could make use of quite a few with Cobra owning friends.

[jwc66k]

Bolt 20438-S78 is strictly a Shelby application for exhaust. The only place 20438-S(any finish) is used is attaching the oil pump to the engine. It is a grade 2 bolt. A grade 5 bolt, 304722-S(2) (8 ea), was used on 260 and 289 engines. It is not a full thread. There is a lot more.
Jim

[Dan Case]

Bolt 20438-S78 is strictly a Shelby application for exhaust. The only place 20438-S(any finish) is used is attaching the oil pump to the engine. It is a grade 2 bolt. A grade 5 bolt, 304722-S(2) (8 ea), was used on 260 and 289 engines. It is not a full thread. There is a lot more.
Jim

Only one part this size, thread, and length was listed in the Cobra/427 Cobra/1965 GT350 parts list in May 1965. May 16, 1965 service parts list: “20428-S78 Bolt, 3/8-16 X 1¼L 427 FORD EA .07 Retail  .05 Dealer” Even though it says “427” the small letter version was used on Cobras 1963 and much of 1964.  The small letter part disappears from Cobras roughly fall 1964. CSX2524 had large letter parts for example.

Small letter part, Cobras 1963 and past mid 1964:

2 each to fix starter to engine

and

3 each to fix alternator bracket to RH cylinder head for CSX2201 and later cars with five bolt engines until about cars finished in the fall of 1964 and later.

Still, none of this information has yet to help turn up any small letter parts except as used parts from Cobras.

Still have not figured out if the small and large letter versions were the same part as far as Ford and or SA was concerned.

[jwc66k]

My sources are more closely aligned with Ford Motor Company documentation, the "AMK Guide To Ford Fasteners, 1966-73", and "Ford Standard And Utility Parts Catalog, 1969" (and the 65 and 66 versions) by Osborn Reproductions than you Shelby reference. What you are seeking is 304722-S7/8. See the AMK website https://www.amkproducts.com/ their stock number B-12643. This grade 5 bolt was used until 12/17/65 when it was replaced by a Ramp-Lock type (ref AMK B-12465). It has the large "F" head marking.
The finish referenced in the Shelby documentation should read "-S7/8" which indicates either cadmium or clear zinc plating is acceptable, and not "-S78".
Jim

[Dan Case]

My sources are more closely aligned with Ford Motor Company documentation, the "AMK Guide To Ford Fasteners, 1966-73", and "Ford Standard And Utility Parts Catalog, 1969" (and the 65 and 66 versions) by Osborn Reproductions than you Shelby reference. What you are seeking is 304722-S7/8. See the AMK website https://www.amkproducts.com/ their stock number B-12643. This grade 5 bolt was used until 12/17/65 when it was replaced by a Ramp-Lock type (ref AMK B-12465). It has the large "F" head marking.
The finish referenced in the Shelby documentation should read "-S7/8" which indicates either cadmium or clear zinc plating is acceptable, and not "-S78".
Jim

Thanks. All the originals in Cobra (small letter until past mid 1964 and large letter afterwards) are black. Max was asked if he had any originals of either, no. We have some reproductions of the large letter part from Max (AMK). This search started about 2010. Many of the bulk fasteners used by SA came through Ford. Many others were AN, MS, or NAS military / aviation pieces SA sourced themselves. Many of the fasteners AC Cars used were WWII / Korean conflict era British air frame hardware pieces. SA used all kinds of aircraft materials (steel and aluminum) and parts for street and race Cobras.

Using the May 16, 1965 parts book is tricky because many parts listed for service are just that, service parts and might not even be the same manufacturer as used in production.

AMK Products has little useful originality wise for Cobra owners and restorers. It is common to find a collection of unopened AMK packages or even a kit or two coming along with a Cobra that just got restored. People buy parts and then find almost none cover the 1962-64 time frame of engines and transmissions in Cobras.  I have been given three collections of AMK parts that didn’t get used once the people working on those three Cobras figured out they had wasted resources. It seems AMK offerings are mostly 1965 model year and later.

In the mean time, if anybody stumbles upon and new small letter parts I sure would like to know about it.  I missed it in my list yesterday but CSX2001-CSX2125 cars used two small letter parts to fix the 1962 remote fuel filter assembly to the LH cylinder head also 1962-63. (Fairlanes used a different hex cap screw.) Four different Cobra owners I am helping currently could use a total 12 small letter parts right now.

[jwc66k]

 I've been doing some quick research, and I belive that there is an error (or two) in the source document you keek referring to.
First: the part number 20438-S78 (read it as 204398-S7/8) is the Ford service bolt, not the original.
Second: 20438-S(none) is shown in the 60-68 Ford Car Parts (aka MPC) as the replacement bolt.
Third: I believe the original bolt to be 304722-S2, based on what AMK states is their 2014 catalog, pg13.
Fourth: I believe the finish is "-S2" (phosphate & oil), or "-S" (no finish). Zinc or cadmium ("-S8" or "-S7") are seldom used in high heat applications as they are toxic, and high temperatures will burn those plating away..
My recommendation at this time is to determine what the original finish was on those cars, and not what is referenced in the Shelby book.
Jim   

[Dan Case]

My recommendation at this time is to determine what the original finish was on those cars, and not what is referenced in the Shelby book.
Jim

Dull black, both versions, multiple original parts from multiple Cobras 1962-65. The large letter part shown in the original post was a lunch pail part (claimed to be, the man has access to lots of assembly line parts he uses in high end restorations) located in Michigan during a late Cobra restoration parts hunt. Handling lunch pail large letter ones transfers black color to fingers. The heads of used ones from Cobras, both versions, sometimes have some rust on them but their threads are normally rust free where they have been protected inside cylinder head threaded holes.

During the past year I have e-mailed pictures to quite a few parts dealers, restorers, and 1963-65 427 Galaxie owners. The only thing anybody has had 'new' are the reproductions of the large letter part as sold by AMK Products. No joy anywhere on the small letter parts as far as new ones go.