In need of engine decoder help!

[RickyPatty]

I have a 66 c10 and I've decoded the VIN already,but I am having a hard time finding out if it is a 230 or a 250. I have read that the 250 came in that year but a few signs point to the 230.

[66Submarine]

Not familiar with that number. Can you post some more pictures of the rest of the engine, including the other casting numbers?

Welcome to the forum, BTW.

[Lowl!f3]

also further away pic for location of distributor please.
only one I find even close is 3877178 and thats a 230 or 250.
However it doesnt look like in your pic that the 3 was ground off the serial.

[RickyPatty]

That was the issue I was running in to. Here are some more pics, hopefully they help.

[RickyPatty]

Another pic.

[66Submarine]

The date code has 6 for the year, so it's a '66 or '76. Given that the truck is a '66, I'd guess it's probably the 250 that came in there. AFAIK all trucks '66 and later had the 250.

A way to tell would be to see if you can determine if the pistons are dished or not; a 250 has dished pistons and 230's have flat top pistons.

[66Submarine]

What is it that makes you think it's a 230, anyway?

[RickyPatty]

When I first started searching for this I found a forum that said if it is a two pulley system it's a 230. Another reason is that it is a base model so If the 230 was available I figured it was that.

[66Submarine]

Not sure what that guy was smoking! Lots of misinformation out there. Anyway, it should be a 250 unless it's been swapped out for a car engine (AFAIK you couldn't get a 250 in a truck in '66, and it would be a special order item if you even could).

[RickyPatty]

So I'm going to say it is a 250 then. Thank you for the help, I'm still new to this and I'm trying to make sure everything's perfect before it goes in storage.

[60-66]

To do this right, look just to the left of the distributor on the machined surface. Clean it off and tell me all the numbers and letters that are stamped there. This will positively ID what it is

[66Submarine]

Originally Posted by 60-66

To do this right, look just to the left of the distributor on the machined surface. Clean it off and tell me all the numbers and letters that are stamped there. This will positively ID what it is

Do you have a list of the engine codes for inline sixes? I've looked and can't find anything online.

[60-66]

Yes, I have all the books to cover trucks.

[RANDY COX]

Originally Posted by 60-66

Yes, I have all the books to cover trucks.

If you don't mind look at mine also.. I know what the first few mean but not the last 2 letters. F0303UH

[66Submarine]

Neat. I'll have to send you a couple #'s when I get them down.

Any chance you'd want to scan them (or take some pictures or something) for the greater good when you get the chance? AFAIK there aren't really any lists of the I-6 numbers available online now.

[60-66]

Originally Posted by RANDY COX

If you don't mind look at mine also.. I know what the first few mean but not the last 2 letters. F0303UH

Hi Randy ! The UH suffix was used from 1965-1969 on 292s . If you give me the casting date, I can tell you the day and month AND year your engine was assembled . Your F0303UH . The F is for Flint, the first 03 is the month, the second 03 is the day. So third month=March 03 or March third day of ?year? The year would be determined by the casting date. Hope this helps. Jon

[RANDY COX]

Originally Posted by 60-66

Hi Randy ! The UH suffix was used from 1965-1969 on 292s . If you give me the casting date, I can tell you the day and month AND year your engine was assembled . Your F0303UH . The F is for Flint, the first 03 is the month, the second 03 is the day. So third month=March 03 or March third day of ?year? The year would be determined by the casting date. Hope this helps. Jon

Ok Thanks. I have 2 292's and one has the bigger plug and the other has smaller plugs. Yea I wasn't sure what the UH meant if anything.

[60-66]

UH basically means its a 292 with manual trans. Some codes are more specific. . Your small plug 292, whats the code on that ?

[RickyPatty]

Alright I cleaned off the plate and hopefully this issue can be resolved. I have CON2 E36

[1Bad62Pro/Street]

http://67-72chevytrucks.com/vboard/s...d.php?t=382583

http://67-72chevytrucks.com/vboard/s...d.php?t=356268

[60-66]

Those numbers are "CASTING" numbers, I need the "STAMPED" numbers right next to the distributor in this location.

[RickyPatty]

Alright I got it this time the STAMPED number is F0506TA

[60-66]

Perfect ! TA suffix is used for 1965 for a 230 six and 1966-1968 on 250 six with manual trans in truck only with that suffix. Now if you can find the casting date we can tell what year. It will read like H 6 5 or A 12 6 just as examples and be about 1/8 to 3/16 tall CASTING letters and numbers . More than likely a 250 if its the original engine to your 1966 truck. Strange how they repeated the TA suffix for both 230 and 250, that's not to common. There wasn't a 250 till 1966.

[66Submarine]

He said it was E 3 6, so that confirms it as a '66 250.

[60-66]

Ok, didn't read that. It falls perfect then. 1966 250. Find the thread of yelmers and he can tell you what month this body 1966 was built. He started a list of all the 66s we have on here.