1. Engines
  2. 2.2L/2.5L Block Differences

This KC article is to document the differences in 2.2/2.5 blocks from year-to-year.

The main differences from the early block to the common block are in the oil pan rail and webbing area.

Here's an early block:
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Compare that to a common block:
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And also a 'Tall Deck' block:
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Early block and Common block side-by-side:
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You can see there is a lot more material in both the common block and tall deck block. In fact, the CB and TD look very similar in the bottom end.

Common block:
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Tall Deck block:
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You can see if the picture that they are very similar in design. The most notable difference is the lack of rod clearance 'notches' in the TD block due to the fact that the TD essentailly ran long LW rods. The TD block is 0.470 taller than a common block, and by reports has thicker cylinder walls, too. They have been bored 0.05" over.

According to 22mopar, "theres a difference of 14# beteen bare common block and bare tall block".

There were also apparently some later castings for service engines that were basically common block in structure, but had the fuel pump block off plate for carb engines.

The T3 block was a common block, but with some key differences. The center oil drain is blocked in the head, and the front of the block has some extra material for the crackcase breather. In addition, the distributor hole was not machined since the T3 used a dual coil DIS ignition system; and the mains bearing webs were filled.
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You can see the breather port of the front of the block and the missing distributor hole and in the middle pic you can see that the main bearing webs are filled when compared to a 'normal' common block.

Here's some pictures of the common block sectioned thru the cylinder bore:
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You can get a real good look at the thickness of the webbing wround the main bearings here.

For further discussion, here are some pics of a DC race block (built, with 4-bolt mains):
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Externaly, it appears to be just an early turbo block, but internally it resembles the common block/tall deck.

Here is a picture of a late common block/early block replacement. It appears to some external similarities to the early block (hollow area under the distributor), but no fuel pump drive. The most notable difference here is the partially blocked water port. Not sure the purpose of this.
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This is a brand new short block I bought from Chrysler. I have more pictures of this engine if needed.
Thanks Randy: GLHS60


There are also differences between the Saltillo (Mexico) and Trenton common blocks:

Mexico block in this comparison is a 94 casting originally 2.5L. Trenton block is a 93 casting and was a 2.2L.
Both are/were TBI engines, hooked up to automatic transmission.

94 mexico
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93 Trenton
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94 Mexico close up showing extra cooling passages.
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93 Trenton with cross drill holes and nothing else.
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another picture of 93 Trenton. its got 1 single extra cooling hole in the center and nothing else.
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And the last pictures of the outside. Mexico block shows a much higher degree of surface finishing and overall casting quality. Theres very little 'garbage' stuck on the surface of the block.
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All that roughness that looks like grease/oil/dirt is actually cast iron splatter and is all over the surface of the block. most removes with a chisel & hammer in large flat chunks.
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another view of the trenton block and surface showing extra metal splatter.
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Moving onto the bottom/inside of the block.

94 Mexico shows an overall smoother casting and better finish quality.
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93 Trenton. lots of casting flash and mismatching on where the halves of the mold didnt quite lineup...
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close up of casting. 94 Mexico
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93 Trenton
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Now the good part.

94 Mexico. Quite a bit of extra metal in that bulkhead
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93 Trenton. Same spot.
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Same bulkhead (#2) 94 Mexico
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93 Trenton
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Now some would say the extra metal in the Mexico block is due to it being a balance shaft equipped engine from the factory. But if you look closely there is enough metal on the trenton block to drill & tap for the extra BS assembly bolts. Just nowhere near as much. For someone looking to add the 4 bolt main caps that could make quite a difference in the overall strength and effectiveness of having the extra boltdowns for the center 3 main bearings.

Final comparison. 94 mexico block, The thickness of the 'shelf' where the bearing sits is nothing less than 10mm thick.
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93 Trenton block. bearing support shelf is considerably thinner on every bearing bulkhead.
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Sorry if I lifted your pics for this article, I have a bunch of saved pictures and can't remember who to credit them all to...
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