U code

[Gene Gamache]

I have an 870 block that has a casting date of E124. The only stamping on the front pad is F0514U. There is no VIN on the pad. This engine is in a 64 that I bought from the second owner. He told me he replaced the block in 1973.
I have been told that the "U" designated a truck block or it was an over the counter block. Does anyone know the answer?
I appreciate your help.

[Dave S.]

Re: U code

Gene,
Colvins Book does not list a "U" code but it only has passenger cars. It may be a truck but someone who has a more extensive library will have to chime in.

[Jack H.]

In 1964...

the 'U' suffix designated RPO L30 for Chevy trucks (327, 8-Cyl) used in C60, S60 and M60 vehicles. So, now that you know the block was originally made for a truck, what difference does that make? I don't think there's a significant market for factory concours restoration of these vehicles...

[Gene Gamache]

Re: In 1964...

Jack, thank you for taking the time to research that for me.

[Bruce B.]

Re: In 1964...

In the Lime Book there are over 320 "U" designations and they are all used in trucks from around 1969 thru 1991.
But I could not find just a single "U", they all had additional letters.

[Jack H.]

Re: In 1964...

My observation is from the Index/General Information section of the 1953-69 Chevrolet Truck Parts Illustration And Special Information Catalog. I still don't understand what benefit it is to know that the 'U' suffix code indeed came from a truck engine...

The NCRS JG books tell/teach us what codes match Corvette. So, if the present engine has a suffix code that differs from what's expected during judging, where's the benefit in verifying the original vehicle a donor block came from????

If the suffix code were from a rare/exotic Chevy/Camaro vehicle, yep I can understand the need for due diligence. But, when it's a 'lowly' truck application, I guess I don't get it...