Hello, new fish here

[55wagon]

409 Id question

This is one heck of a site for a guy interested in the old "W" motor! Anyways I have always fooled around with small blocks and don't have a clue about the grandfather big block. I recently came across a guy saying that he has a "special" 348 bored out to 409 that came out of a '63 belaire and only a couple hundred of these "special" motors were made. I figured he didn't know what he really had so I checked the numbers and I'm a little stumped as to what this motor is. Everything was looking good until I ran acroos the suffix code.
Block 3844422
Head 3814690
Intake 3814881
Suffix QG (this is what's throwing me off)
Is this a '64 409 425 hp? Or is it a '64 409 340 hp with different heads and intake? Thanks in advance

 

[Tom Kochtanek]

The latter

If I'm interpreting the numbers correctly, it appears as if this was a 340 HP passenger car motor, with an automatic trans behind it. The heads have date codes as well (you have the high perf setup there) and the 2x4 intake fits nicely on those heads.

It looks like a different set of heads and intake were added (not unusual), but you still have a nice setup there. Hopefully they are in good condition (many were destroyed in the 60s - wonder how?). Let us know if you get them and need advise on reconditioning. There is lots of experience on this board

Cheers,
Tom K

 

[55wagon]

So the next step would be to check the cam. Would the 340hp cam and hydraulic lifters work on the 425hp heads?

 

[JokersBel]

55wagon, I see it the same as Tom. Also, i'd check out the suffix code REAL GOOD, if you haven't all ready done so that is. If any rust may have set in, that code can be a pita to see. The way I see it, the possibility of mistaking a QG for QB (the 425hp block to go with the heads and intake-hopefully) could be done easily, especially if the engine is detailed and painted over. If it were for sale and painted, i'd scrape it to know for sure if any doubt. As far as less than 100, and that it's a 348, I think you are right he doesnt know.

I'd be VERY happy with a setup like that! Don't get me wrong...Jim

 

[Tom Kochtanek]

Regarding that "special" 348 --> 409

If I am not mistaken (others will correct me with the appropriate wisdom), the 348 was made into the middle 1960s for trucks and such applications. I would suspect GM would stick with the thicker and more modern mid-60s 409 casting techniques, but would bore these "truck 348s" to 348 specs, not the 409 specs. Thus the idea that these were "special". I suspect they were in fact common and across the board for 348s made in 1962-65.

But of course you've got other suffix and casting codes on the block you are looking at. Those "underbored 348s" would likely be "3857655" and have the TD, TE, TF, YM, or YP stamped on the front pad. Correct me if I'm wrong, I've never seen a 348 from that 62-65 era (I am hopelessly stuck in the period 1961 and 1962 and hope to remain there .

Best,
TomK