Incorrect Block/Head Combination

[rkd77]

The teardown of the 348 for my '58 Impala seems to show a block/head combination that isn't right according to the casting directory on the site.

My block is a 3751872 and the heads are 3732791.

The notes for the 3751872 block show:

Notes: Only used for 1958. Note-this will not work with #3732791 heads as it is the first block to include cooling holes for the spark plugs.

Do I have incorrect heads for this block??

Thanks,
Randy

 

[tripower]

I believe the first 872 castings did not have the cooling holes but did have the passages cast in the block and the holes can be drilled out on the block to use the later head castings that did have the cooling around the spark plugs.

 

[oldskydog]

The first 872 blocks did not have the cooling jacket cast in. Around Feb 58, the second version of the 872 block had the cooling provision but was not drilled unless it was a 315 hp version or a truck engine with the new plug cooled heads.
What is the casting and assembly date of your block?

 

[tripower]

The first 872 blocks did not have the cooling jacket cast in. Around Feb 58, the second version of the 872 block had the cooling provision but was not drilled unless it was a 315 hp version or a truck engine with the new plug cooled heads.
What is the casting and assembly date of your block?

Cecil, Thanks for clarifying that so, after February 58 the castings should have the passages.

 

[rkd77]

Thanks!! This is really helpful.

Casting code of the block is B2458. So Feb 24, 1958. How would I identify the assembly date of the block??

 

[rkd77]

Another question. The Magnafluxing showed cracks in the lifter area. The machinist didn't think it was worth fixing. Picture attached. Is this block junk?? The yellow lines are graphics highlighting the locations of the cracks.

 

[Phil Reed]

The block is totally junk with cracks in those areas!!!!

 

[Tom Kochtanek]

If the block is original to the vehicle, it might be worth it to set it aside in case some future owner wants to reunite the car with it's original engine.

In terms of repairs, it would be less expensive to begin with a new block and heads.

Depends on how you feel about originality.

Good luck!
TomK

 

[rkd77]

Good point, Tom. Maybe I should set it aside.

I had been thinking about making it a planter (assuming it was junk). Maybe grow some chiles in the cylinders. My wife thinks this is a stupid idea, which I'm pretty used to!! My brother grows chiles in an old toilet (no longer used for it's original purpose).

Randy

 

[oldskydog]

Another question. The Magnafluxing showed cracks in the lifter area. The machinist didn't think it was worth fixing. Picture attached. Is this block junk?? The yellow lines are graphics highlighting the locations of the cracks.

View attachment 20466

Too bad on the cracks. At least it confirms that by Feb 24, the 872 was being cast with the cooling jacket.

 

[Bungy]

Just to narrow it down a bit, the latest 872 block I've seen with no cooling pads is A2858 and the earliest I've seen with the cooling pads is B1058. So it was sometime between then.
Too bad about your block, that's a lot of cracks. Just out of curiosity, did it have any other cracks? Cylinders or outside of block?

 

[tripower]

Thanks!! This is really helpful.

How would I identify the assembly date of the block??

To bad about the cracks. The stamped suffix number in front of the passenger head is the assembly date. The first part of the number will start with T=Tonawanda, then some numbers=assembly date, then 1-2 letters=HP, Transmission and, Carburetor. http://www.348-409.com/suffix.html

 

[rkd77]

Just to narrow it down a bit, the latest 872 block I've seen with no cooling pads is A2858 and the earliest I've seen with the cooling pads is B1058. So it was sometime between then.
Too bad about your block, that's a lot of cracks. Just out of curiosity, did it have any other cracks? Cylinders or outside of block?

Bungy, no other cracks that the shop told me about. I haven't seen the block myself. The machinist suspected overheating at some point.

 

[rkd77]

Too bad on the cracks. At least it confirms that by Feb 24, the 872 was being cast with the cooling jacket.

Can this cooling jacket be seen on the block? Are there holes in the block where the heads mount?? Are there corresponding holes in the heads to get the coolant nearer to the spark plugs??

 

[rkd77]

Here's the big question: how to get this car back on the road? I want the car to be kept basically original although disc brakes and an overdrive transmission instead of the Powerglide have been part of the plan someday. So I want a 348. Seems like I have a couple of options.

A) Get an already rebuilt engine (on E-Bay and other places I've seen)
B) Get an engine that needs a rebuild and hope that it doesn't have cracks.
C) Find a block that someone's already torn down (the machinist said that my heads, intake, rods, etc. are OK)
D) Other

Any input would be apprecieated. Thanks,
Randy

 

[oldskydog]

Can this cooling jacket be seen on the block? Are there holes in the block where the heads mount?? Are there corresponding holes in the heads to get the coolant nearer to the spark plugs??

Yes, they are the two small holes on the head mounting surface on either side of, and above, the spark plug holes.

 

[Marilynbubbletop]

We had a bad 409 block w/ cracks in the same areas as well.. However, an old time welder said he could brass those right up and it wouldn't leak water into the oil galley or vise versa.. This was 3 years ago and the engine is up and running perfectly fine w/ no leakage, seapage anywhere.. Opps !! It only runs a quarter mile at a time tho, but times 3 years ?? That's a lot of hard running on what was suppose to be a planter.. I went ahead and changed the damaged 409 block w/ a known good one for our 61 belair 2dr. Good Luck !!!

 

[region rat]

There are some good ceramic sealers out there. Did the motor show any signs that water was already leaking? I had a phone # of a guy wanting to sell a 348. I think it was a 58 or 60.

 

[Marilynbubbletop]

There are some good ceramic sealers out there. Did the motor show any signs that water was already leaking? I had a phone # of a guy wanting to sell a 348. I think it was a 58 or 60.[/quo

These are cracks (See Photos) of are 409 block.. These have been all brazed up and it doesn't leak.. Yes, we're using a ceramic sealer inside since day 1. Although, we went ahead and took a huge gamble on this working out, it was a crap shoot as well.. Motor was running perfectly fine and we tested it for a good hour or so before we purchased it.. It wasn't until the machine shop called us back w/ the bad news about the cracks.. On the other hand, you can find a good condition 348 block out there w/ no problem and not have to worry about it leaking and doing all your hard work over again..