Why does everyone think the 230 400 block is the ONLY 400 block worth building

Just venting a LOT.... I had to go through 3 -400 blocks to find one that did not need a cylinder or 2 sleeved due to core shift for the 470ci I'm building. Guess what, 2 of the blocks were "230" blocks Both had horrific core shift.. the 830- 74 block I'm building has very consistent cylinders walls averaging .190 -.220 on the major and minor thrust sides

How could this be? It's not the world famous holy grail of all Mopar blocks! The """"230"""" Block

Venting because I have a non sonic checked 72 std. bore 630- 400 block for sale on Craigslist that apparently is nothing short of a boat anchor according to all of the Super Duper Mopar Master Engine Builders here in metro Deroit that have responded to my post on Craigslist..

The only "better" thing was the increased material in the main webbing of the block. In all my years of sonic checking stock big blocks I have never found a pattern or reason to choose any block over another. Core shift is an issue with ALL of them, you just need to sort through a few to find a good one. My last "good" 440 block was a 77 block. Thicker than all the earlier ones I checked. I made the mistake of not checking the 440 in the dragster, in the end cylinder wall was .096" thick. Unfortunately I did not need to use the sonic checker. Oh yeah this was a 70 block.

Early blocks can be thin, later blocks can be beefy. No rhyme or reason as to why.

One of the best block I've ever seen I have on hand. It's a 1976 440 casting.

I acquired a 67 block with a hole similar to Al's in a lot buy. Guess what it was? .088 wall thickness at .030 over. Yikes!

Just the opposite over here in PA from what I've seen...guys who have a 230 block, sitting in their shed getting dripped on every time it rains, and wants a fortune for it cause "this is the GOOD one everyone wants!".

Yours is a good buy, if I was closer I'd pick it up just to have. Someone will jump on it!

How much are you asking? If it's much more than "haul it away" money, ponying up for a sonic test to prove its worth could be the next step. Then whether it's good or junk, you'll know what it's really worth.

Was that a major or minor thrust measurement, or a non thrust? I got a couple of holes that have OK thrust thicknesses, but the sides are thinner than I'd like (but it ain't blowed up yet).

There are Two types of 230 blocks. The Preferred ones have the thicker mains then the standard 230. But with that said the bores may still be the same as all the others even though its a different casting.

The Infamous ones were made between 4/4/71 to 10/10/71

Did the two 230 blocks that you had sonic checked fall within that monthly time period??

You need to remember the early "cold weather 230, made from 06-1971 to 12-1971, only have thicker main webbings than the later 230 blocks
You are correct on always sonic checking any model 400 block before starting to build any half serious race or Hi Po street motor
One of the first 400 block I built was furnish by the customer and he said that he had it check by a machine shop in central CA and it was good, it split the #1 cylinder on the engine dyno after several pulls. I had Pettis Performance sonic test it and every hole on the drivers side was horrible, less than .060 remaining after boring it 4.375 I had them try to sleeve all four holes on that side and it would even hold a sleeve
I found a stock bore 1972 630 block locally and had it sonic tested, it was a minimum of .170 on all cylinder on both the major and minor thrust sides
I bought my Dakota 1000 sonic test meter right after that Works great, last a long time

Here, the numbers "230" have become the buzz numbers for, "I'm building a 800 horsepower 512 low deck street motor and that's the only block that will hold together" I'm really considering pulling the post off Craigslist, having the block bead blasted, clearcoat the block and making a table out of it for my shop..

440 Source has the following information including photos, discussing what several have stated.

http://www.440source.com/blockinfo.htm

I will add, I've read that the casting / foundry process improved as well as the iron used during the later years of production. Perhaps that may explain why the more consistency with the later-year block quality (i.e. less core shift) in some people's opinion.

Well for a 800 hp a real "230' would be a option if the bores checked out. They Really, Really had the beefiest crank Thick main Webs compared to any other 400,s

Now the bores, probably the same scenario, never know.

Again, What/Which 2 "230" blocks did you have sonic checked??


What dated timeline, Between 4/4/71-10/10/71, or other???

I can tell you that I really did not care about the mains. Didn't even look at them. I measured one bank of cylinders on one of them and gave it back to my customer. The other 230 block was worse in that both cylinder banks had a few measure below .100 on the major thrust sides. I will take a nice consistent thick cylinder wall over thicker webbing on the mains all day.

I ve got one, 7/72. Standard bore, one hole checked at .082 on major thrust, 3 other holes not much better. Dave

I have the 230 block as well 12-6-71. #1 and #8 or 2 were thin. #1 was the thinnest on major at .120". Was gonna have it sleeved but best machine suggested to just fill it. So i did. Filled with hard block within 3" of the deck. Mostly street 511 but with see a few passes at the track. Hope it holds up.

Been beating the snot out of my "non" 230 block which came out of a 72 truck and the sonic #`s were real good most everywhere except a few non thrust areas...........7000+ rpm's a LOT and thousands of street miles and many passes over the years.........STILL kickin azz............

I am running a non 230 also, it's actually a 1974 530 block that sonic'd out at over 300 on all cylanders at stock bore size, so much for thinwall castings and core shift.

Over 0.300"? You just plain got lucky. There aren't many that will have those numbers. Actually I question the measuring technique.

To the OP: There are more 230 blocks that are not the thick web blocks than ones with the thick webs. There are probably more thick web blocks that have that one bad hole than those that don't. So it's a needle in a haystack.

Keep the faith. There are smart people out there as well as the knuckleheads and a-holes.

R.

Hey, I found you! $250 seems to be a pretty good price, wish I was closer. My motto is "A man cannot have too many blocks aging in the back yard!"

Somebody will buy it, Craigslist doesn't charge so let it ride.

I'm attaching your picture.

Best Regards,
R.

My #'s were in the .250-.300 in some areas but the average was around the .220+ range............