I wondered if anyone could decode these engine numbers for me.

Engine #1
V0538TDJ

Engine #2 has two numbers
V0428TDR
C8A168860

Forgot to add that these are the numbers found on the pad at the front of the passenger side cylinder head.

quote:

Originally posted by fastracer482:
I wondered if anyone could decode these engine numbers for me.

Engine #1
V0538TDJ
TDJ 1980 350 van & bus,a/t L LS9 155 4 C-10 to 2500

Engine #2 has two numbers
V0428TDR
C8A168860
TDR 1972 350 conv. cab, a/t 175 4 K-10 & 20

Looks like both are 4 bolt main truck 350 engines.

https://nastyz28.com/gm-chevy-...e-codes-suffix-7.php

Thanks.
I’ll bookmark that site.

quote:

Engine #1
V0538TDJ

Breakdown of Engine Code: V0538TDJ
V – Flint, Michigan engine plant

05 – Month: May

38 – Day: 38 is not a valid calendar day, which suggests this may be a misread or misstamp, or possibly a dealer replacement block or over-the-counter service engine.

TDJ – This is the engine suffix code, which determines the application, transmission, and horsepower rating.

TDJ Suffix Code
Suffix codes were reused across years and platforms. Based on known GM suffix codes:

TDJ (most commonly) refers to:

1970 350 CID V8

Application: Camaro or Chevelle

Horsepower: 300 HP

Transmission: Turbo 400 (automatic)

Carb: 4-barrel

Usage: High-performance small block

quote:

Engine #2 has two numbers
V0428TDR
C8A168860
TDR 1972 350 conv. cab, a/t 175 4 K-10 & 20

1. Engine Assembly Code: V0428TDR
Breakdown of V0428TDR:

V = Flint, Michigan engine plant

0428 = April 28 (assembly date)

TDR = Suffix code

TDR Suffix Code
You're right about its application:

TDR (1972)

Engine: 350 CID V8

Application: C/K-series trucks (K10, K20)

Vehicle Type: 4WD, likely K10 or K20

Induction: 4-barrel carburetor

Transmission: Automatic

Horsepower: ~175 HP (net, post-1971 rating system)

Body Style: Likely Conventional Cab

2. Partial VIN or Engine Serial: C8A168860
This appears to be a partial VIN or engine unit number.

C = Likely Chevrolet truck

8 = Possibly 1968 model year — but this conflicts with the 1972 TDR suffix.

A = Atlanta assembly plant (commonly used in GM VINs)

168860 = Sequential production number

Possible Explanation:
This may be a reused block or a remanufactured engine where the original partial VIN remained, or someone restamped it at some point. It's also possible this was a 1968 block that was reassembled in 1972 for a truck, though that’s less common.

Summary:
Engine Code V0428TDR matches a 1972 350ci small block used in Chevy K10/K20 trucks with a 4-barrel and automatic.

C8A168860 is likely a partial VIN, possibly from an earlier vehicle (like 1968), suggesting this engine may not be 100% numbers-matching if that VIN isn't from a 1972 truck.

This setup was factory-rated at 175 HP net.

No V.I.N. sequences were stamped prior to 1969, EXCEPT Special Hi-Performance engines in Corvettes and Camaros, iirc.