Hi guys, I am in need of some advice on 6.9L block differences. I have checked the net and dug up quite a few threads on the subject, yet I still have more questions than answers. The one useful piece of literature I found concerning s/n breaks was this:
Now for my questions:
1) There is a lot of web chatter concerning two main s/n breaks, the first being 59209 and up. Am I correct in the assumption that this is the "A" block vs. "B" block break, with the 59208 and earlier having the block heater cracking problem?
2) The second s/n break often discussed is 173828 and up. Can anyone verify if this is what people are referring to as the "85" block? The chart above indicates the crank case received upgraded ribs on its sidewall.
3) In the experience of those here, how important is the 173828 s/n break? I am going to be doing a fairly extensive 6.9L build and I don't want to put my "goods" into an inferior block. The block in my truck says 6.9D U2U 010464*, and is a Ford crate engine installed in a 1986 truck. In spite of the 7.3L style oil filler and rocker arms, I take it this is a ~very early block... and not one I want to use even though I expect it to be in excellent condition. I also have a second 6.9L of dubious origin and condition with the s/n of 6.9D U2U 154017*
If it checks out as rebuildable, would the 154017 block be a suitable foundation for a semi- "performance" build up (i.e.,110cc IP, BW S360 turbo, Stage 1 cam, etc., ~300 whp, boost in the 20's)? ....or should I seek out a late 6.9L block at a junkyard? There are only two currently at my local yards, one is clearly pre-173828, the other has a non-sensical rebuilders tag on it.
If I am going to shell out good money for another block I would prefer the type with bolt-in piston oilers (s/n 237016 and up), but sadly northern Arizona does not have many bone yard 6.9's to choose from. If the consensus is to seek out a later block, then perhaps a trip to some larger out-of-town junkyards may be warranted. Thanks all for any insight or info you may have on this.
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Now for my questions:
1) There is a lot of web chatter concerning two main s/n breaks, the first being 59209 and up. Am I correct in the assumption that this is the "A" block vs. "B" block break, with the 59208 and earlier having the block heater cracking problem?
2) The second s/n break often discussed is 173828 and up. Can anyone verify if this is what people are referring to as the "85" block? The chart above indicates the crank case received upgraded ribs on its sidewall.
3) In the experience of those here, how important is the 173828 s/n break? I am going to be doing a fairly extensive 6.9L build and I don't want to put my "goods" into an inferior block. The block in my truck says 6.9D U2U 010464*, and is a Ford crate engine installed in a 1986 truck. In spite of the 7.3L style oil filler and rocker arms, I take it this is a ~very early block... and not one I want to use even though I expect it to be in excellent condition. I also have a second 6.9L of dubious origin and condition with the s/n of 6.9D U2U 154017*
You must be registered for see images attach
You must be registered for see images attach
If it checks out as rebuildable, would the 154017 block be a suitable foundation for a semi- "performance" build up (i.e.,110cc IP, BW S360 turbo, Stage 1 cam, etc., ~300 whp, boost in the 20's)? ....or should I seek out a late 6.9L block at a junkyard? There are only two currently at my local yards, one is clearly pre-173828, the other has a non-sensical rebuilders tag on it.
You must be registered for see images attach
You must be registered for see images attach
If I am going to shell out good money for another block I would prefer the type with bolt-in piston oilers (s/n 237016 and up), but sadly northern Arizona does not have many bone yard 6.9's to choose from. If the consensus is to seek out a later block, then perhaps a trip to some larger out-of-town junkyards may be warranted. Thanks all for any insight or info you may have on this.
