Radiator Hose Decoding question

[ORIGLS6]

Does anyone here have any idea how the codes on radiator hoses decipher? There doesn't seem to be any standard format that I can see.

Example: two 1970 Chevelles, both from the Arlington Plant, and built less than two weeks apart. The upper hoses have the same part number; 3942453 SV which is for a four core radiator, but the smaller codes vary drastically. One reads "EB 76 EX 5 0 02 20 7 0 K3" and the other is "76 EP 50 EB". All the print on these hoses are very clear so I know I'm not missing any numbers. And the lower hoses on these same cars read 3959188 SZ P/N and "C129 70K3" and 11139K3" respectively.

BTW, I noticed Red Alert still has the original upper hose so I'd be interested to see if the smaller code is still legible, and how it fits into this mystery.

Thanks in advance for any replies.

P.S. I'd also be interested in any pix you might have of original hoses, particularly '69 & '70 Chevelle and Nova.

[mrrec]

Dennis:
A number of different suppliers (Goodyear, Gates, Goodrich probably and more) provided hoses to Chevrolet. As you note, the part numbers and suffix codes are the same as Chev specified. Problem is, each supplier used his own date, plant and shift codes, etc. Some date codes are pretty obvious - others are tough. Font and size also varied.

02 20 and C12 are Feb 20th and March 12. I believe the "70" may indicate the model year.

Not much help here, but it's what I know......
Dave

[ORIGLS6]

Thanks! At least that part makes sense.

[Verne_Frantz]

Dennis:
In addition to what Dave said, Chevy also required each of it's outside manufacturers (suppliers) to uniquely identify their parts. Some source suppliers used their actual name, some used initials, or a logo, and some just used some cryptic code unique to them. The engineering dept kept records of all the supplier codes. IF a certain part had common failures in the field, the zone reps who supported the dealers would relay the supplier's ID back to engineering.

Verne

[ORIGLS6]

Sounds like this could get really confusing.

The ones discussed above should get rave reviews though. Still in service and holding up very well after 38 years!

Thanks to both of you.

[Mr70]

This practice wasn't just limited to radiator hoses.I've seen it used also on PCV,Neoprene Fuel line,A/C freon,Hi-psi Brake hoses and even rubber Vacuum lines too.