400 blocks

[Paul Secoy]

Hello all, I have read varying opinions on what the "good" years of 400 blocks are, some claim thicker bores, others claim more material around the main webs depending on year.
The one I just picked up for my build is an April 1973 block. It was the only one I could scare up on short notice, just wondering how it ranks.

Thanks

 

[kramer]

Hello all, I have read varying opinions on what the "good" years of 400 blocks are, some claim thicker bores, others claim more material around the main webs depending on year.
The one I just picked up for my build is an April 1973 block. It was the only one I could scare up on short notice, just wondering how it ranks.

Thanks

This a good write up on the year differences of 383,400,440 blocks.
http://www.440source.com/blockinfo.htm

 

[Lefty71]

This discussion goes on and on. There are not bad blocks at a certain date in time, so to speak. You just have to grab one, get it checked and if it's good, chive on. If it's not choice, grab another and try again. Some will say, that the early 1971-72 #3614230 casting is the best, and owners will ask a premium for it, but they reality is that unless you a building an outright monster, you will probably be fine with any casting. Mother Mopar parts are strong. It takes a whole lot to cause issues with the block, they arn't gonna split in half like a small block Ford trying to make 550 horse. You can bet there are more than just a few folks here running a 400 based killer stroker that had no issues building up the block. My 474 is a '73 400 and it's done just fine by me. HTH, Lefty71

 

[33 IMP]

Definately read the 440source write-up. It evaluates strength by casting number, and tells where to look on Your block for more meat/less meat.

 

[Paul Secoy]

Thanks for the replies, I read the linked article and will use it to ID my particular variation when I get to tear it down this weekend.

 

[33 IMP]

Let us know what you find.

 

[wyrmrider]

bore as little as possible like .020
short fill
you can sonic check but if you keep the bore down
it should be fine

 

[Paul Secoy]

Hit my quota at job #2 early so I got to tear it down tonight. I was hoping for one of the "230" blocks, as they supposedly ran into 1973, but alas, it was not to be. My block # is 3698630, which according to the 440 Source article, is second best, and much beefier than any 440 block around the main webs. This motor has been run for years with a 250 shot, and has what looks like a set of stock 906's up top. The block looks fine, and I think I did ok for my $100 investment. I am debating whether to go with aftermarket main caps or not..

 

[1 Wild R/T]

After seeing the set of BRC aluminum main caps posted recently I don't know that I'd jump to quickly...

https://www.forbbodiesonly.com/moparforum/threads/my-year-is-done.180202/

 

[33 IMP]

Interesting . I've got a standard bore 230, but the main caps are gone. I was thinking about aluminium caps, but now I'm inclined to aftermarket steel. Who makes them besides 440source ? I have nothing against 440source parts, just looking at alternatives.

 

[Paul Secoy]

Well, I called the machine shop today and they won't do aluminum main caps, so that settled that There are two local fellows running stroked 400's with spray that are in the 1,000 HP range, and both are running stock caps with studs and a girdle. They have been together for years, and seem to be going strong. My stock, short stroke combo should be a little easier on parts, so I guess I will follow their lead.

 

[1967coronet440]

1000 hp stock block, yikes.

 

[wyrmrider]

detonation can break anything

 

[dvw]

If I was spending my hard earned cash it would not be on a block that had seen 100s of 250 nitrous shot hits. It's been working the main webs .
Doug

 

[wyrmrider]

Mag and/ or dye

 

[Paul Secoy]

It will be checked out well, I wish I hadn't passed on 400's all these years, they aren't as easy to find as they once were. I collected 383's and 440's, but never a single 400.
The two guys I mentioned running high HP may just have been lucky, but they both had similar combo's, (I believe 451 strokers), and neither ever had a problem, just studs/girdle/stock caps. I believe the one fellows engine dynoed at 780+, and then a 250 shot. Both were/are 8 second E bodies. I am assuming my shorter stroke, less RPMs, and turbo Vs. nitrous should work in my favor. I"ll be the first to know.

 

[Lefty71]

opinions on what the "good" years of 400 blocks are, some claim thicker bores, others claim more material around the main webs depending on year.

It is well known that the bottom of a 400 is even tougher than a 440. Hopefully someone has'nt already posted this, but I would have to say that a high hp build with a 400 iron block would likely be "Uncle Tony Approved" lol.

 

[Paul Secoy]

I bumped into that video a few days ago I'm hoping my block checks out and I don't get too greedy with the boost controller. Thanks.