1966 Hipo Auto Trans Identification

[kkravik]

I'm looking for some help with the identification of a 1966 Hipo Auto Trans.  Specifically, what are the casting codes on the C servo, tail shaft and main body next to selector rod.  I have found some information on line, but would rather hear from someone with first hand knowledge.  Thanks in advance for your help.

[J_Speegle]

Think we're going to need to know when the car was built at San Jose to help with the correct servo cover. Guess you have already read that thread. If not the search feature should help there 

Just about all of the external other pieces are the same as 100's of thousands others but sure others have the casting numbers not sure if your going to go as far as date coding each

[6s1640]

Hi kkravik,

See the link to the Bob Mannel article on the HiPo C4, reply No. 6.  It is an excellent article.  Also remember the "C" servo came from a Ford truck and was not initially designed for the HiPo C4.  It was designed for sever or heady duty service in the truck.  The larger piston would help hold the tranny in a lower gear with a heavy load going up hill.  There are two versions that can be ID'd by a fat "C" or a skinny "C".  The Mannel article only shows the fat "C".

Best of luck

Cory

http://www.saacforum.com/index.php?topic=1263.msg10480#msg10480

[Karguy]

Here are some pictures of "C" servo covers. The fat "C" cover is a C5TP number for 1965 and very early 66 cars, not sure of the change over date. Also, a picture of a C6TP "C" cover, skinny "C". 
Hope they help.
Karl
6S281

[kkravik]

Thanks for your replies.  My '66 GT350 is a December '65 San Jose build so I assume it should have a skinny C servo.  Where I'm confused is the code on the main trans body, near the selector shaft is C4AP.  My understanding is this would be a C - 1960's; 4 - 1964; A -generic/Galaxie; P - auto Trans.  If it was correct, shouldn't it be a 6 for 1966 and Z for Mustang? 

I don't have a concours car, nor will I ever make it one, but I would like to have it right.  Given how difficult it is to find the appropriate trans maybe I should focus on just finding a skinny C servo.

Kerry

[Karguy]

This may help, I know for a fact the transmission that was originally in 6s1669 had a C6 part number (see picture).  I'm not sure when that car was built at San Jose but maybe you could research it and see if it helps you with dates for your car and your transmission application. 6S281 was built at SA approximately Oct 15 65 and came with a C5 case number.
Karl
6S281

[DennyD]

Hi Kerry, These may help too. You'll see on the second photo my C-4 had a 2-66 date. I believe 6S1568 was a mid-March 66 assembled car.

[TLea]

Thanks for your replies.  My '66 GT350 is a December '65 San Jose build so I assume it should have a skinny C servo.  Where I'm confused is the code on the main trans body, near the selector shaft is C4AP. 

6s392 Dec 65 build has C4AP tail and fat C

[Karguy]

How about the cast part number on the main case of the transmission? The one near the shifter shaft.
Also C4AP?

[kkravik]

I mistakenly transposed the main case and tail codes.  The tail has the C4AP code and the main body has the C6DP code with a 8/65 build. 

Kerry

[gt350hr]

   Casting numbers were not  HiPo specific. That is a very important thing to remember. As in the case of 289 engine blocks , not EVERY C5AE-E block was a HiPo. Same for the transmission castings. The valve body castings were C5AP on both regular and HiPo versions. Yes the separator plate was notched on the HiPo and the regular was not. The other internals are only identifiable by there differences, as they do not have part numbers.
BTW , the '67 HiPo valve body was also notched ( differently) , something that Bob M. didn't include in his awesome book.
    Randy

[Karguy]

 Randy, agreed that the casting numbers do not indicate anything about what performance level the transmission is from, K code, a code, c code etc, no difference in the cases. It would interesting to know for reasons of correctness which casting numbers in terms of C5DP,  C6DP etc changed in different build dates from San Jose. I for one would be very interested in knowing exactly when Ford changed from the C5DP to the C6DP cast cases on the early K code 66 cars.
Karl

[gt350hr]

   Karl,
     Ford castings were revised as needed and when they were the casting number changed . Raw castings  were then machined to various "possibilities" specific to a part number. Casting numbers did NOT have to change every year. A casting number "could" change but the "service part number" wouldn't. And vice versa the part number could change but the casting number wouldn't.
      I seriously doubt either case was HiPo specific as I said before. There isn't any reference to a special case for the HiPo in the Master Parts Catalog. ( mine is from '72). The change would have been for all C4 cases. The only way to get a feel for the change date would be to look at the main case blueprint which would note the change.
     Randy

[Karguy]

Randy, thanks again but I believe in my comment I said essentially what you are now saying which is that no C4 cases were made specifically for hipo use.
Thanks, Karl

[gt350hr]

   Correct. Besides the multiple rebuilds I have done over the last 40+ years on them , myself and others have all the hipo specific part numbers detailed in the Master Parts Catalog . Valve body , servo and governor are the major component differences. There was an obscure torque converter ( ink stamp ID) but when I cut mine apart 40+ years ago I saw no distinct , or measurable differences from a 'normal" C4 converter. At the transmission assembly plant , the components were simply substituted for the non hi po parts at the assembly "stations" when a run was made. A common order was 100 units at a time.
   Randy