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Pinecone 03-14-2013 06:49 PM

307 or 350 - codes confusing
2 Attachment(s)
have a parts car i'm about to buy. back stamp says 5.7LG SGI (see pic...350, right?). but front stamp says V0626TAD - the TAD translates to early 70s 307 in every list i can find. to make it more interesting, heads appear to be Type O for a 305 (see other pic).

either the engine is confused or i am...any help greatly appreciated.

68NovaSS 03-14-2013 08:11 PM

Can you get the cast numbers off of the bellhousing area and the numbers on the heads under the valve covers? Is that stamped number off the motor pad in front of the head?

DoubleVision 03-14-2013 08:34 PM

5.7 is a 350. These blocks were not stamped with the liters until the 80's.
Production on the 307 stopped in 1973. Your engine will have a 1 piece rear main seal which started in 1986 and the 307 was long out of production at that point.

Pinecone 03-14-2013 09:46 PM

DOUBLEVISION - so the bet is 350 mid to late 80s? that would square with what seller said, which is the guy that sold it to him took it out of an 84 truck.

do you agree the head end casting looks like the Type O 305 head? i guess they could have gone that way to bump compression but it must die over about 4500rpm due to lack of air - unless they did some porting. or maybe those arent 305 heads?

intake and carb is a matched edelbrock 600 and rpm best I can tell. ought to be a little more interesting than the 283 I have in my 64 impala SS right now at any rate. we think the trans is a turbo 350.

thanks for the help

Pinecone 03-14-2013 09:47 PM

68NOVASS - i can get all the #s when i pick it up saturday. i'll update the post with any pics you need to make a positive ID.

DoubleVision 03-15-2013 03:34 AM

I'm unsure what you mean by the "O" casting of the head. The heads have the same markings as the 416 casting number 305 heads.
the "5.7" marking is proof positive it's a 350 block, as I don't believe anybody would have took the time to try and recreate that casting to make anybody believe it's a 350 covering up the fact it's a 307. As said, look at the rear main seal, You can bet it's a 1 piece. From the early 80's on into the late 90's there was only 2 small blocks in production, the 305 and 350.
I've seen many blocks identical to the one you show in the picture, in fact I have two of them, both of mine are late 90's Vortec blocks.
I understand how the "TAD" code is throwing you off, but you have to remember, there are many suffix codes out there that have never been verified and placed into the records. You also have to keep in mind since 1955 there was over 90 million small block Chevy's produced, and on many occasions, different cubic inch engines carried the same suffix codes and they did so sometimes a few years apart, and sometimes decades apart.
There isn't anything else stamped on your block other than the casting number that will verify it's a 350, but by seeing "5.7" on yours is all the verification I needed. I used to have a 1985 350 block out of a truck. It was a 2 piece rear main seal, and the casting number was on the drivers side of the bell housing flange just as all old school small blocks were. This block also had the dimples in the center of the lifter valley which would later be used as the spider retainer bolts on SBC's equipped with a factory roller cam.
On every 1986 and up small block I've seen, they all carried "5.0" or "5.7" in the spot the casting number used to be, such as is on yours.
1986 was the same year the rear main seal was changed to a 1 piece design to eliminate the warrenty problems created by the leak prone 2 piece seal.
If you'll look on the bell housing flange you'll find something that looks like this example:
A 9 0
A - January, the month. 9 - January the 9th, the date. 0 - The year, 1960, 1970, 1980, 1990, to verify the year, look up the casting number to see what years that casting number was produced. There will also be a clock which tells you what time it was casted. You'll also find a arrow pointing at one of the three letters which are D for day shift, N for night shift or A for weekend shift. There was only a day and night shift as the plants, as they do today, work on 10 hour shifts. Now you know more useless information.

Pinecone 03-19-2013 02:38 PM

casting # on block is 14093638 - which looks like an 87-94 350 with (prob) a roller cam. I've double checked the stamp on the front - V0626TAD. All the "TAD" translations I found are 70s 307s, which this is not according to the other 2 stampings.

Gotta love it...

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