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Strongest block

51K views 97 replies 35 participants last post by  '89dodge  
#1 ·
I'm going junk yard shopping soon for a new block to replace my cracked 53. I was just wanting some info on wich blocks are sronger, or better yet wich blocks aren't much stronger than the 53.
Some one once told me that the 55 blocks are prone to cracking, allthough not as bad as the 53, is there any truth to this?
I've also read that blocks with a series of casting #s that are hard to read are the strongest. True or not?

thanks in advance for any info.:thumbsup
 
#5 ·
Chuck, would this block be a boltup replacement or will I have to make things fit? I've never heard of this? We're scrapping a couple of buses at work, they have 54 and 55 block ISB's And I may be getting one for next to nothing, Think I should still look for the IH block, I'm not doing anything serious, just a 450horse tow rig. lol.

Jesparza, look on you're block just above the oil pan and directly below the oil cooler housing. or on the driver's side of the block just to the rear of the power steering pump. the casting #'s will be in one or both places.
 
#6 ·
It would bolt right in. I know of one guy who has an IH block in his 2nd gen. Kindof a nice surprise when you realize what you have.

Any block casting other than 53 is fine. The blocks, IIRC, were cast in Brazil at the Cummins block casting plant and machine 53 produced thin walls that are prone to cracking. 54 or 55 should be fine for your needs.

-Chuck
 
#10 ·
Well I just got word from a friend who feels that Ag blocks aren't found in 24 valve trucks, just 12 valve trucks. So from what I can tell, VE and P pump 12 valve trucks might have Ag blocks, 24 valves I can't prove either way at this point. Maybe someone else with more experience with these Ag blocks will chime in.

-Chuck
 
#18 ·
Where would the IH be cast on the block? I'm gonna go see if my '92 has it.

As far as 12v and 24v blocks interchanging, I think they do. Only difference is there will be a place to bolt the mechanical fuel pump on the 12V, the 24V has the boss in the casting but it's not machined out.
 
#12 ·
Thanks alot chuck, Are the 12 and 24v blocks the same? I was under the impression that they wouldn't interchange.
 
#16 ·
Update: The engine I wound up with has only a "5" cast where the brazillian castiing #'s would be, and it has the International logo (diamond) cast on the front of the block.
Is it true? did I end up with an "AG" block??????
 
#20 ·
The logo I'm refering to is the newer International logo that looks like a square tipped up on one corner, not the logo w/ the letters I and H, just wanted to make sure that was clear, I'lll post pics as soon as the block is back from the machine shop.

This logo is cast on the front of the block, just above and to the right of where the cam goes into the block, as viewd from the front.

I'm not sure of the year, but this is indeed a 24V VP44 engine, It came out of a low floor, rear engine, 19 foot transit bus. There is a boss for a mechanical, cam driven fuel pump, and it has been machined out. It had a cover/ wiring bracket bolted in place where the mechaical fuel pump would go.
 
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#22 ·
Yes, it is inside the the gear case, the cam might have to be pulled out to see the logo that's on my block.
I didn't notice it when I took the engine apart, I noticed it after it had been cleaned, and at the machine shop.
 
#25 · (Edited)
just looked at a freinds 12v (98) he has a small "5" on the passanger side about half the size of my 53 on my block.. does that indicate he has a IH block? tried looking on the driver side for the numbers first but was too much gunk:lol3:
 
#27 ·
Hey Nick, long time no see!
Yeah, the 53 isn't faring too well, not over heating yet, but coolant temp fluctuates ALOT! and keeps the underside of my truck green:rofThe crack went from about 3.5 to over 10" That's what happens when a guy races, and sled pulls with a cracked block.:lol3:

White99, I'll post pics as soon as I get the block back from Greeley Auto and Machine. hopefully by the end of the week. If my memory serves me correct, the "5" was only on the injection pump side of the block.
 
#28 ·
ok.sounds good.id really like to find out and learn more about this "5" on the passanger side of the block,it may be on the drivers side as well but there was so much gunk i couldnt really tell n didnt feel like takin another shower after looking for a number i already saw on the other side haha. keep me posted i would really like to know.:beer
 
#34 ·
:lol3:im waiting for someone to chime in on em as well:w: i looked at a freinds 98 12v n he had a small 5 on the passanger side n wanted to know if it indicated anything, i tryed lookin on the driver side but was too much gunk for me to keep fishin around..so now im just hopin someone sees the thread that knows about em:beer