What blocks do I have

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pentastarpro

pentastarpro

speed trials
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I've built my share of small mopars and started to check my "B" blocks I hoarded for years to finally get working on my first stroker. I have 2 early 70's that both mic @ 4.320+/- which is the bore for the 440 "RB", these should be 4.340 minimum.
The markings are:
casting- #3614230-6 dc- 11/23/71 Id pad- #H400 114E pan rail- #C201766
casting- #3698630-400-5 dc- 5/15/72 Id pad- #J400 728E pan rail- #3104971
I have a 78' 440 motorhome block sitting next to the B blocks and am well aware of the differences. How could I have B blocks with a 4.320 bore?
This one has me stumped.
 
Jim Lusk said:
Double check your measuring equipment. The casting numbers are 400 blocks.
Click to expand...
Thanks for the comment Jim. That was my first "reason check". I have a good set of Starrett inside and outside mics. Ultimately I dug out the 440 block and set it next to the "B" blocks and all three measure 4.320 +/- a few thousands. I have carefully examined both blocks to detect if there are sleeves or something odd but have found nothing abnormal. The next step would be have one sonic checked but that's pretty expensive if I have some oddball Mopar item. I can't check the stroke as the old cast cranks were disposed of years ago. I can only check the witness lines in the bore and guess from there. Just looking for any good ideas.
 
that 230 400 block would be the way to go,judging buy the casting date,might be thick web,those thick web blocks only made 4 months,i have one thats 12-1-71 not thick web,and another early that is
 
I bought these many years ago off an engine rack at a wrecking yard that was closing. They were both complete (one dodge, one ply) with tags that indicated less than 90k miles. He didn't remember how long they had been in the rack but was many years. I broke them down right away and was happy with the condition, not baked or grungy. I threw away the cranks as I always intended to make them 451ci with Speed-o-motive kits. There are new players in town now and it is time to do it. I guess a sonic test of the 3614230 is next. I have been on the 440source web and "yes" it is the thick wide base main support style. Time to get busy.
 
Got it! Sorry for the confusion. Got a snap gauge which is easier than an inside mic and everything is "good in WHO land".
Block reads .020 - .027 oversize with .005-.007 taper. I'll shoot for .040 oversize which should allow enough meat for a clean cut. I like the idea of a 500ci kit but will stick with the 451ci.
Thanks for the comments which allowed me to get my head straight.
 
Also, the 440 block I was comparing to was bored .040 + .005-007 ware so is very close to the "B" block measurements.
 
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