Technical Best heads for A sbc 400

I got A 400 small block that I've had for years,if I was to build it what heads should I be looking for.

 

What are your goals?

 

Strong street motor in A light truck ,some time at the track. I have been hearing
that vortec heads are good to use.

 

X2

 

If I build it,probably bore it .030 over and use forged flat tops,stock bottom end,turn or polish crank,motor is still together but did her it run years ago.The oil pan is off,its A 2 bolt main.I don't know what cam I would use,but fairly big.

 

What ever non 400 heads you run you will have to drill the steam ports in to have them work with the 400 block. That's a given.
Vortec/ not Vortec might depend on if you already have an intake. They work good but if you already have your intake of choice that means you have to turn around and buy another intake or cobble yours to hopefully work as was done back when.
I don't know about "best" but the Flo-Tek 102505 from Speedway for 400 each assemble may not be that bad of a deal for a hot street motor with flat tops Figuring what most guys want for a set of decent performance 202 heads used plus the cost of a proper valve job including new guides and springs and it eats the cost of those up pretty quick.

 

Yep. Vortec will limit you on intake and you can not go real big on cam.

 

Ok thanks, I knew the 400 had to have steam holes in the heads.I don't have A intake for it .

 

MR. 48- Can we agree to friendly disagree? I find this info false, as proven by myself. I believe the steam holes that need to be "drilled" to fit a 400 block is an old wive's tale. You can bolt on any aftermarket, or HP old school factory head on, and it will be fine. Camshaft, and compression WILL affect cooling characteristics, as well as a proper cooling system....
Vortec is another animal- dedicated intake, and limited on camshaft.....
I've done such. No holes drilled, a very high compression ratio, and a big solid roller cam.
Was able to travel at least- calculating distance here, 125 miles in summer heat, and no worries. Temps stayed in the 180-190 range the whole way.....Not to , but I will, say it ran low 10's in the 1/4 mile with my "driving/street" duty set up... Pure street would be a lot more forgiving, and easier.
The only thing with a 400 block, which I would take ALL day, is a lil worrysome of a 2 bolt main, because you can only rpm them so much, and that depends on the build up.
S0- To the OP= yea/nae..... up to you to decide on YOUR engine. I'm just speaking from experience is all, and would do the same thing again......Hot Rod On!

 

My coupe, blown 406 , no steam holes drilled. Victor heads. Has never overheated.

 

If you do run the Vortec heads,the whole “can’t run a big cam” issue is null and void if you fork over a couple of bucks for the seat cutting/guide machining tool from Comp Cams,then you can run any sbc springs,and put some decent valve seals on there,without your retainers smashing into them.
These heads work really well.We’re a few weeks away from swapping a set onto my Son’s Malibu,and we got them for $150.
$50 for the tool,a few hours labour,a few hundred bucks for performance friendly valves and a touch up on the valve job,and we’ll be ready to go.
We’ll probably spend another $50 on screw in studs,just to be safe.
That’s not a lot of money for some really decent running heads.


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I'd still drill them holes... Chevrolet did it for a reason so I'd plan on doing so!!!!!

 

If you use flat top pistons, a 64 cc head will make the compression ratio around 11:1. Look for 72 cc heads

 

I called Aerohead (a division of Indy cylinder heads) and talked to their tech guy. I got my cast iron heads with hard seats, 2.02/1.60 stainless valves and good springs/retainers for $660/pr delivered to California. You can customize them up or down as required. Helluva deal and they were really nice out of the box (being a skeptic, I just had to pull some valves to check the workmanship)

 

EQ350H

 

I ran my old truck at the dragstrip today. This is its 19th year at the strip and I drive it there and home. It is a small block 400 with stock 400 heads, stock low compression pistons, performer intake, Holley spreadbore carburetor, thumper cam, and cheap headers. It runs mid 13 second quarters with a best ever of 13.1. I shift at 5100 rpm. In the 25 plus years of driving this combination, my only failure was a flattened cam lobe, because no one told me about the removal of zinc from the oil.

It is not fast, but it is fun, it has longevity, and it was cheap.

Speed cost, how fast do you want to go?

John

 

Maybe you don't absolutely need to drill the steam holes but I don't see any downside. If I recall correctly, since 400 sbc chevy blocks have siamesed cylinders; the steam holes are supposed to prevent steam pockets (air bubbles) from forming at the tops of the cylinders by providing an escape route. Besides, I believe I'm correct to say that, you can still use them on any other block that doesn't need steam holes by just using the correct head gasket. So five minutes with a cordless drill = peace of mind. BTW some of the holes need to be drilled at an angle, you can find instructions on the net.

On another 400 topic, don't be scared of two bolt main 400 blocks, they're stronger than the earlier 4 bolt versions since the outer bolt holes remove material from a critical web area. I run a destroked 400 and use main studs instead of bolts. My 380" motor has a pretty big solid roller and rpms like crazy. I've beat on it for years and the block is holding up just fine.

 

Hey I want to thank all of you for some very good advice.
The 400 I got,I bought it off by dad when I was 14 years old ,first summer job I had and took some of the money and gave him 200$ for the motor .I have had the motor in his building for 24 years,and hear lately been thinking I need to do something with it.
It will probably be around the first of the year before I buy any parts or machine work to it,but trying to get A idea of the parts I want to use.

 

If your bookeeper isn't influencing you then Air Flow Research.

https://www.airflowresearch.com/195cc-sbc-street-cylinder-head/

 

I've been messing with 400s for years, have 3 of em in 3 different vehicles now. as far as steam holes I always drill em with stock cast heads for street use, with aluminum heads Ive tried it both ways haven't had a problem but usually these engines dont see stop and go traffic. The 2 bolt block is the better block if your worried you can convert it to splayed 4 bolt. If your gonna buy pistons anyway shitcan the short 400 connecting rods and put 5.7" or 6.0" rods in it.

 

I'm not an engine guy but it's time for my 400 story. Streetrod. Never raced. Ran my 400 for 10 years as pulled. After rebuild, incl mild cam, started getting antifreeze in no. 1 cylinder. Learned from oval track guys that they all run 400 engines to be at top of class. They told us that decking the block during rebuilt weakens the deck in the crotch between nos. 1 & 3 where a steam hole and head bolt are close together. Torquing the head bold distorts the deck enough for my leak. They told us they always plug steam holes when building a 400. Not needed. They said there is a crate engine available with siamese cylinders and no steam holes. Don't remember which it is. I took their advice, plugged all steam holes. Never a problem. Never see 200 degrees in very mild street driving. No racing.

 

In view of the fact that you intend to drive the vehicle on the street as well as the strip, I agree with the people that are saying drill the holes, it isn't that big a deal.
My son bought AFR aluminium heads for his 400, and they came with the instructions to drill them. I am reasonably certain that they would not included the instructions if they did not have a good reason for doing so. From my experience, by not drilling them, you have everything to lose and nothing to gain.
Just remember that steam will expand to 1600 times the original volume at standard temperature and pressure at 212 degrees. If you super heat the steam, it continues to expand. This increase in volume can cut the flow of water in the top of the engine, cavatate and overheat the pump. damage the water pump seal, and cause other serious problems such as head warpage.
I have a O/T car with an engine that requires considerable effort to eliminate the air from the system when the antifreeze is changed. If there is any air in the system at all, the engine overheats and makes it necessary to completely cool the system down and re bleed it.
Bob

 

Interesting tid bit, Edelbrock recommends drilling only the lower steam holes when installing them on s 400. I am going to SEMA next week and intend the boys in the Edelbrock booth their reasoning on that.

 

If you drill them. 2 are straight and 2 are at an angle.

 

There are six on each side of the engine. 3 on the intake side and 3 on the exhaust side. 3 are drilled straight down and 3 at a 30 degree angle toward the 3 that were drilled strait down. You will eventually have a problem with the head gasket either between the 3 and 5 cylinder or the 4 and 6 cylinder if the holes are not drilled. This is where the exhaust valves are close for the cylinders mentioned and a lot of heat is created. The steam holes are relief for the dead ends that were created by the siamese cylinders. It allows flow to continue into the heads and eliminate a steam pocket. Steam is a very poor conductor. My 2 cents.


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Blueprint makes a new 400 block both wet and Siamese.

 

They look like the go-to guys for Chevy heads. Great deals it seems...

 

This is what I have on my 355. Summit carries them with an intake & gaskets, hardware, etc. Not a bad deal at about $1600 for everything. 64 cc combustion chamber, Speedpro flat tops .030 over, CR is close to 10:1.
http://dartheads.com/dart-product/shp-23-180cc/

 

A hot 400 SBC can easily use a head with 200+ cc intake port volume. 180cc will work OK, but will run out of breathe real quick. My 383 uses 210cc heads with 2.05 intakes. Makes 525-550hp. Your 400 could run even bigger heads. I run Profiler heads cast, machined, and assembled in Ohio. Great heads. Choice of combustion chamber volumes and choice of valve sizes. It was a couple years ago, but mine were $1260 to the door. Check 'em out. The only thing about aluminum heads is you must zero deck the block to get proper quench at .035 to .045". Aluminum heads require a thick composite head gasket such as felpro 1003 at .041 IIRC. A thin shim gasket will fret the heads due to cast iron and aluminum having different expansion rates. Aluminum heads will let you run a little more compression without detonation. Use a compression calculator to come up with the volume you need in the combustion chambers. Google Wallace Racing Calculators. They have a good one. I wouldn't run more than 10.5:1. I would run 5.7" rods with those forged flat tops.
That 400 is capable of an easy, streetable 500-550. If you're worried about looking traditional paint them orange.

 

I also had a magic 400. The idea was to use up parts that I had and build the baddest MF on the cheap.
Here's my formula.
Bored .030"
Stroked with offset stock crank to 3.83" (offset ground to 2.000")
This makes 415 cu. in.
Early 327 small journal 5.7" rods
KB Hypereutectic Pistons KB139
Theoretically the pistons should stick out of the bores by .023" (ours were out .005" with a skim cut on the decks)
PAW Cam (lots of lift short duration)
Advance cam to 102 degrees intake centerline
Dart II iron heads
Holley 780 Vacuum Secondaries
Holley dual plane

Ran like 'Jack the Bear' with stock exhaust manifolds
If I did it now, I would use a Comp hydraulic roller and long tube headers
This is a torquer, 5500-6000 rpm.