Does anyone know for sure what the main case casting number would be for a C4 originally from a '79 model truck. I have seen a number something like D4OP-7006-AA or similar for a '74 model but haven't seen a similar number starting with D9 for a '79 model. I realize these numbers might have changed when there was a revision. So were there no revisions and Ford continued to use numbers beginning with D4 or D5 on cases through '79 or should the '79 case number start with D9?
Also is the casting date/year found inside of the two small circles behind the Ford logo script above the shift lever on the drivers side?
Thanks in advance everybody, I sure appreciate any info.

 

This is the casting number found on the TRANS case, it does not ID the trans. Casting numbers are foundry marks, cannot be cross referenced to Ford part numbers.

See pic below: TRANS ID tag bolted to the servo cover. It may be missing by now.

Why do you need this info?

 

Thanks for that information ND, I was hoping you would respond. I have a nice '79 f100 that's all original except for the trans which the previous (original) owner swapped out (and scrapped) the original C4 for a C6 instead of just rebuilding it. Even cut and welded the damn driveshaft, at home of course, to accommodate the longer C6. How it didn't fly apart and kill someone defies all logic considering it was driven on the interstate numerous times. Anyway, I was hoping to find a C4 out of a '79 model to put back in it. Just don't know how to tell what year they are. I read on some other sites that the two cast-in small circles on the drivers side of the case above the shift lever contained the year it was cast with a 2 digit year such as 79. May just be a load of b.s. as far as I know though, although on my original 72 F100 the number inside of one of those circles is the number 72. Could just be coincidence i guess. Thanks again for sharing that information and I'll make sure to look for those id tags.

 

1978: First year that 300/302 were available with C6, but the C4 was also available.

1973/77: NSS located on steering column, same for all A/T's.

1978/79: NSS located on left side of trans case, C4 uses a different NSS than C6.

 

Ahh...I see. That is very useful info that I did not know. Thank you for sharing it. I really appreciate your help

 

When I was looking for a specific year C4 for a friends bronco I was told there are about 11 different variants and not all are worth rebuilding. He looked for certain ones to build and modify into a C5. Looked for some thing like case fill, and pan ????. Can't remember the pan part.

 

He was probably referring to "pan fill" which is what a 79 f100 would have. Yes, these C4's can get really confusing especially when you are looking for individual pieces such as extension housings and output shafts, lol.