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RB Block ID

Nick Bruno

Local time
4:25 AM
Jul 2, 2020
Reaction score
Fresno, Ca
Any block experts out there? I pulled mine from a ‘69 Charger (not original) and stripped it down. The date code appears to be 4/5/68 and as you can see it has the strengthening ribs over the freeze plugs which I didn’t think started until later blocks. And all the blocks I’ve seen has these ribs stop about halfway across the blocks where these run the full length. Also, the engine mount tabs appear beefier than the blocks around this age that I’ve seen. Finally, check out the upside down “A” stamped on the block ID pad. Someone told me that means the factory bored it oversized. Any ideas what this block may have come out of? RV? Truck?
In any event, I’m leaning towards building a street able stroker, maybe 512. I’ve been reading a ton of Andy Finkbeiner’s material and I think it suits what I’m looking for. If anyone knows anything about this block, do you think it’s a suitable start for this (assuming no cracks or whacked out measurements)?

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Look up 440 source , look thru their web site . On the top of the web site to the left you will see About us and other info . When you open this page go down to where you see Misc. General info. The first article is every thing you wanted to know about engine blocks and more . Quite a bit if info on 383 thru 440 blocks . Hope this helps John
"On the side of the block just above the freeze plugs, sometimes you will find a strengthening support or "rib" cast into the block. This was started in the 1969 model year on 440's (E 440 code on the ID pad), or approx mid '68 casting date."

Looks good so far. You'll want to get it to a machine shop and have them hot tank it and run a sonic check. If everything is good then you have a winner. If it is a standard bore block then just go 0.030 over to build a 505. If that block is 0.020 over (that is what the A means) then it might not clean up at 0.030 over so you might need to go 0.040 or more. That is where you need to work with the machine shop. These days I'd pay a little extra for custom pistons rather than bore a block 0.060 over right off the bat. We used to do that back in the 80's but that is because there were blocks everywhere back then. These days it can be hard to find a good 440 block.
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