Thread: 406

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heys guys, on a earlier thread, i was planning a 396 build, i have thought about it some and ive changed my mind. i am now deciding on building a 406. where can i find a good 406 block? and any combos any body may have will help. thanks

If you can afford it, go aftermarket. If not, search Ebay until you find a 2-bolt main, preferably a '509 casting block. The combo's for a big inch small block are almost unlimited, depending on what you want out of it. Eagle makes some nice rotating assemblies to start the bottom end with.

I agree with fever get a nice aftermarket block if you can afford it. I had to go through 3 400 blocks before I found a good one. With those short rods in there the outside cylinder walls catch hell. The bad blocks I found all were wore out .020 on the outside wall only. I didn't want to go .060 on a 400 block so junked em. The guy I had doing my machine work, Hotards just happened to have a good 4 bolt 400 block. I didn't really want a 4 bolt 400 block but just couldn't find a good 2 bolt block. So far so good with the 4 bolt block, but I'm not put much of a load on it since I have it destroked to a 377 using a 350 crank.
Good luck on your find. I wish now I would have put more stroke to mine, can't beat the torque on a true 400 or larger stroked engine.

Originally posted by mad hooker
heys guys, on a earlier thread, i was planning a 396 build, i have thought about it some and ive changed my mind. i am now deciding on building a 406. where can i find a good 406 block? and any combos any body may have will help. thanks

Why not build a 395 small block?

well i want just a litle more power.you guys know of any good places to look for them?

also, i was looking at darts small block 400. are these different from the originals? and would it be safe to bore it to a 406? i know the 400 was bad on over heating because of the siamesed water jackets. so im a little worried about boring it and using it it my build. i was reading a article in chevy hi performance. ''muscle mouse'' and the numbers their engine put out are exactly what i want, so i want to build one like theirs, but would it be safe to use?

With a Dart block, you could build whatever you want. Their cylinders are not siamesed and you don't need steam holes. They have bigger water jackets and no overheating problems. Dart says you can safely bore them to 4.180 with no problems. They are much stronger than stock.

Originally posted by mad hooker
also, i was looking at darts small block 400. are these different from the originals? and would it be safe to bore it to a 406? i know the 400 was bad on over heating because of the siamesed water jackets. so im a little worried about boring it and using it it my build. i was reading a article in chevy hi performance. ''muscle mouse'' and the numbers their engine put out are exactly what i want, so i want to build one like theirs, but would it be safe to use?

The World products Mo-town block will go 4.25 bore X 4.00 stroke in other words a 454.

My .030 over 400 block doesn't have an overheating problem. I personally think that alot of the overheating porblems assiciated with the orginal 400 is those short rods and all of the extra friction on the cylinder walls created by them. Just my thought on it. I know of quit a few folks that run 400's that don't have any overheat problems. I don't even have both sets of steam holes drilled in my heads as per edelbrock and no problems with heat.

is there anything i should watch out for, it sounds like there pretty sound.

Originally posted by mad hooker
is there anything i should watch out for, it sounds like there pretty sound.

Yes,large amounts of core-shift.To make a 400 stock block live don't over bore it past .030 over,have it sonic tested if you think you will ever push it past 500 h.p.,run the water by-pass kit if you think you will spend alot of time sitting in traffic , run a very good radiator, run a 6.0 rod to reduce side wall loading,watch the rear main bearing,400's are know having a problem there,run the best head gasket you can,make sure the block and the heads are square,follow you head torque specs very carefullyand please say about 100 hail Mary's.I was kidding about the last one or was I ?Please don't get mad.

Originally posted by erik erikson
The World products Mo-town block will go 4.25 bore X 4.00 stroke in other words a 454.

at this point why? the big block 396 can be bore past .030 and the 454 big block bored past .030 to it would be cheaper and so would the 396 build . if you can find a good 400 small block??? may be harder to find than a good big block and with the big block you do not have to worry about the short rod

Originally posted by pat mccarthy
at this point why? the big block 396 can be bore past .030 and the 454 big block bored past .030 to it would be cheaper and so would the 396 build . if you can find a good 400 small block??? may be harder to find than a good big block and with the big block you do not have to worry about the short rod

He had talked about building a 406 and then he had a couple of questions about the Dart block.I was giving him the Mo-Town block as an option.I think it would be hard to beat a 496 for bang for the buck.

Originally posted by erik erikson
He had talked about building a 406 and then he had a couple of questions about the Dart block.I was giving him the Mo-Town block as an option.I think it would be hard to beat a 496 for bang for the buck.

yes it would