Need some help on some numbers.

[ArkGL01]

I have found a Cheyenne SWB 402 truck. Nice truck original interior but they added buckets and has original AM radio. No glove box data sheet because they did paint it before he got it. The 402 has original linkage and carb. Guy has owned the truck for 20 years and knew who had it before that for 5 years. The only problem is the number on the motor is TO327TKX.. TKX runs to a C20 truck. I know they put c10 motors in some of the c20s but did they put C20 402s in the c10s. The truck was built in st Louis. I don't want to buy a non matching numbers truck. Any information would be appreciated.

[ole dollor]

I know of several 402 motors from the factory in a c-10 trucks. I think they were 1972 model .

[ArkGL01]

But did they take C20 402s and put them in c10s?

[ole dollor]

Originally Posted by ArkGL01

But did they take C20 402s and put them in c10s?

not sure on that questions , I always heard that if its in a truck its a 402 , if its in a car it was a 396...?

[RenoKeene]

Your engine was built March 27 in Tonawana. 1972 L-47 402, 210HP
The 402 is a 30 over 396 and there is no 1/2 ton, 1 ton etc version. All the same block.
Pull the valve covers and decode the heads. The intake has a casting number and the block casting number is on the back of the block where it mates to the tranny.
NastyZ28 web site has all this info.

[SS Tim]

Originally Posted by RenoKeene

Your engine was built March 27 in Tonawana. 1972 L-47 402, 210HP
The 402 is a 30 over 396 and there is no 1/2 ton, 1 ton etc version. All the same block.
...

While they are the same "block" there were different production versions for the various applications with build and dress out differences. Its these differences that the suffix code denotes. After all while a C30/4 speed 402 engine can be redressed to be a production C10/TH400/NB2 (A.I.R.) there a number of different parts involved.

[leddzepp]

You will never be able to prove "numbers matching" on these trucks.

[leftybass209]

Originally Posted by leddzepp

You will never be able to prove "numbers matching" on these trucks.

Exactly. Put another way, if the truck was born with a 402, you'll never be able to put a specific block and specific truck together, they weren't serialized that way. A date code on the block should be before the truck manufacture date; that's as close as you can get.

[RenoKeene]

My 402 intake was cast 11 days before the block casting date so I can assume they were assembled together.

[RenoKeene]

Some things you can look for:

Remote power steering reservoir
Exhaust heat shield located on bottom passenger side of cab
Big block engine perches
4 row radiator and correct hold downs
Duel exhaust frame hangers
Bolt in high hump trans cover
TH400 trans (came with the 402)

[SS Tim]

Originally Posted by RenoKeene

Some things you can look for:

Remote power steering reservoir
Exhaust heat shield located on bottom passenger side of cab
Big block engine perches
4 row radiator and correct hold downs
Duel exhaust frame hangers
Bolt in high hump trans cover
TH400 trans (came with the 402)

A good list to go from but there are some important verifications the need ot be made first.

Is the VIN plate attached with stainless rosette rivets?
Does the frame VIN match the title?
Has the frame been altered? Are you SURE?!!!

If everything is looking good then you can proceed with the Reno's list then move on to the component level, application and date coding carb, distributor, trans and rear end. The casting date of the block itself really dosen't help as a stand alone number but it can help confirm the heads and intake are probably original to the engine. But they must all preceed the engine build date.


Notes for Reno's list
Be sure the exhaust hangers are rivited to the frame.

High floor hump is factory with weldnuts on the bottom of the cab.

[ArkGL01]

Is there any other way to find out if it was born with a 402? I believe it is a matching truck. All sheet metal is original. It has had a repaint. Interior except seats is original I just didn't want to buy something and find out different. I appreciate the help.

[ArkGL01]

The vin is CCE142S204180 if that helps.

[gipper]

Originally Posted by ArkGL01

The vin is CCE142S204180 if that helps.

That is not a correct vin number. It is a 17 digit number.

[leddzepp]

Originally Posted by gipper

That is not a correct vin number. It is a 17 digit number.

There is nothing wrong with the vin number, it has all the correct numbers and letters it should have.

[SS Tim]

Originally Posted by ArkGL01

The vin is CCE142S204180 if that helps.

It does and it dosen't as I said earlier.
To break it down

C Chevrolet truck
C Conventional cab the typical Pickup/Blazer/suburban series of vehicles in a 4x2 or RWD.
E V8 307, 350 or 402, thats a lot of engines.
1 5200-7500lb GVW vehicle a 1/2 ton or series "10"
4 pickup, either a fleetside or stepside
2 1972 model year assembled in 71-71
S St Louis assembly plant
204180 unit serial number

[SS Tim]

Originally Posted by ArkGL01

I have found a Cheyenne SWB 402 truck. Nice truck original interior but they added buckets and has original AM radio. No glove box data sheet because they did paint it before he got it. The 402 has original linkage and carb. Guy has owned the truck for 20 years and knew who had it before that for 5 years. The only problem is the number on the motor is TO327TKX.. TKX runs to a C20 truck. I know they put c10 motors in some of the c20s but did they put C20 402s in the c10s. The truck was built in st Louis. I don't want to buy a non matching numbers truck. Any information would be appreciated.

Without a build sheet and a protect-o-plate it is impossible to data an engine as original. But with a plate you can narrow an engine down to a single production day by virtue of the assembly code and suffix. If you have that specific code then it is very likely the original engine, but that cannot be proven! Of course with the restamps out there many "correct" and "original" cars are not, just recreations.

In your case there is no way to determine wnat assembly code engine your truck had. Nor even the model built. VIN alone only will give us the series and basic body style beyond the year and plant.

The engine assembly number does indeed decode to be a Tonawanda engine built on 27th of March. The suffix TKX however denotes it to be an application for a C20 or C30 truck with a TH400 transmission. It may very well point to a truck built from a C20 donor.

The suffix codes for a C10 or C20 would be TKB or TLM. It is important to note the usage. C10 trucks or C20 Suburbans (a passenger vehicle in this case) have emission controls not found on C20 trucks or C30 trucks. Thus the different suffix codes to account for differences in carb setup, igniton timing, TCS and in the case of the AIR versions (suffix TLM in this case) the air pump and related parts.

[RenoKeene]

Excellent info Tim.

[briscuba]

Excellent thread guys..! I had a similar question a while back. I bought a 1970 CST/400 SWB with a 402. The numbers do in fact indicate 402 ci., Chevy truck, 1970. The only reason for a shred of doubt is that the motor is painted blue. Someone at some point did a rebuild... The list of things that Reno mentioned is SPOT ON! If all these things add up, you are on track. BUT... to be 100% sure is really impossible without SPID or Build sheet (or in some very rare cases original sticker).