ok well i can get a 1980 chevy truck 1/2 ton with 4" lift new 33s..4 speed...but it has a 400 SBC in it...i was told the 400 is a P.O.S or a motor that chevy put out like the 351M and 400M that ford put out...anyway


is the 400 a good motor or not..any power...anything like a 350? what do you all think....

everyone claims that they overheat all the time too. i got a 73 400 that i got out of a impounded truck so i dont know the history and it is a kick ass moter. ive had a bunch of 350s before this engine and the 400 is way better. never overheated it either, even idling around offroad in 4wd in 100 degree heat.

i dont have any specs on it, but my old truck it was in was a 6000lb 82 suburban had 373 gears and 38inch tires. it would spin the tires from a launch, just like one turn of the tire. and towed a few cars with that same set up and you can bearly tell they are there. great torque

I think you should pull that POS out of the truck and tell me where I can come get it and take off your hands. I'd be doing you a favor :)

In stock form, they're not a whole lot to shout about, but you can say the same thing for pretty much any smogger era v-8.

Aside from that, they're a really popular engine, lots of aftermarket parts available for them (cant really say that for the ford 400....i know). Depends how crazy you want to get with it, but at the very least adding headers, an intake, 4 barrel if it doesnt have it, maybe a cam would definitely wake it up.

I've also heard a lot of about them overheating, but i've known a few people who've had them and none of them have had a problem with it. One thing i always read was to drill steam holes in the heads cures that problem.

The 400 is a true SBC just like the 350, meaning all the external goodies swap around just like any other SBC. So, it's not like a GM version of the 400M.

Personally, I absolutely love 400's. I have a .040 over 400 in my mud racer right now & there's a clear performance advantage over my competitors who have similarly built 350's. I also had a completely stock 400 in a '56 Chevy pickup with a TH400 & manual valve body. It didn't have a lot of top end, but could get to 60 MPH in 6 seconds flat. Not too shabby for a 200HP engine :laughing:

I have had a couple in drag cars, and one in a mud toy. Never had any problem with overheating. They are good in my book

stroke it & cool it & call it done. make good low end.

^^^^ thats good advice.

you can put a 3.875 stroke in one, and have a 421.

Honestly, the guys that bitch about the 400 being a hot running engine are the same dumbasses that cant buy the right headgaskets when they "rebuilt" the engine.... or the same guys that didnt drill the heads for water when they put the 305 heads on it... like the 305 heads would support the airflow requirement of a 400...

they deserve what they get.

Run it, drive it, beat it. 400s are a great engine. just a bunch of uneducated fucktards that cant figure out the business end of a wrench giving bad info out that provides the bad reputation.

I have one in a fj-40. There arent many carborated motors I would trade it for. Well for that fact I wouldn't trade it for any carb motor.

The motor is a truck block, 4bolt main, with 202 fuelie heads. It screams, and has never over heated,even on the trail.

^^^^ thats good advice.

you can put a 3.875 stroke in one, and have a 421.

Honestly, the guys that bitch about the 400 being a hot running engine are the same dumbasses that cant buy the right headgaskets when they "rebuilt" the engine.... or the same guys that didnt drill the heads for water when they put the 305 heads on it... like the 305 heads would support the airflow requirement of a 400...

they deserve what they get.

Run it, drive it, beat it. 400s are a great engine. just a bunch of uneducated fucktards that cant figure out the business end of a wrench giving bad info out that provides the bad reputation.

x18732972394

I cant agree more. They are a great motor.

In stock form, they're not a whole lot to shout about, but you can say the same thing for pretty much any smogger era v-8.

Aside from that, they're a really popular engine, lots of aftermarket parts available for them (cant really say that for the ford 400....i know). Depends how crazy you want to get with it, but at the very least adding headers, an intake, 4 barrel if it doesnt have it, maybe a cam would definitely wake it up.

I've also heard a lot of about them overheating, but i've known a few people who've had them and none of them have had a problem with it. One thing i always read was to drill steam holes in the heads cures that problem.
Prime example of misinformation. And no offense to you RJR99SS! But the 400's HAVE to have the steam holes drilled

they are crap you should send it to me and a case of beer just for taking it off your hands:smokin:

x18732972394

I cant agree more. They are a great motor.


Prime example of misinformation. And no offense to you RJR99SS! But the 400's HAVE to have the steam holes drilled

That is correct........for 400 heads. Many overheating "problems" came up when peeps swapped non-400 sbc heads on a 400 WITHOUT drilling the steam holes.

Although I would think....with POOR cooling system maintainance.......a stock 400's steam holes could become plugged with crap over time or lack of use.

Overall IMO the 400 is a fine motor. They are torquey which comes from the generous stroke and large piston top (bore). They were all used in heavy ass cars/trucks and could actually pull down some good fuel mileage if run efficiently because they make good low end TQ. Use it, you'll like it!

x18732972394

I cant agree more. They are a great motor.


Prime example of misinformation. And no offense to you RJR99SS! But the 400's HAVE to have the steam holes drilled

Yeah, but if you use different heads they might or they might not.

400s are a bitchin motor! been around many in my lifetime. definatly get it

The sbc 400 got the reputation of overheating and cracking in the 70's when people paid less attention to maintenance and coolant quality. When meatheads fill their radiators with ditch water, rust flakes clog up the steam holes, causing problems. I worked in a machine shop in 81-82, and I saw a lot of cracked 400 blocks with clogged steam holes.

Properly built and maintained 400's are as reliable as any sbc. Dirt track racing is dominated by 406 sbc's. And they are incomparably superior to the 400m which is probably the worst v-8 in at least the last 40 years. Your ford freinds must be telling you the 400's are similar to prevent you from switching. Just remember, no one is more enthusiastic than a convert!

400 chev is the best starting point for a stock block sbc
the siamese issue is a myth, every big aftermarket block is siamese bores


400ford is a great motor too, just not as ford sold them.
lose the open chamber heads (go with aussies) and put some compression into it.
the cooling system is far better then anything chev made until the reverse cooling stuff came out, canted valves are far better then wedge.

Yeah, but if you use different heads they might or they might not.

AFAIK 400 were the only early SBC to use the steam holes. So if you swapped heads from anything other than a 400 you needed to have the holes drilled. Its a very simple operation but one that is overlooked by many people.

like the 305 heads would support the airflow requirement of a 400...

they deserve what they get.



I know someone who put those on a high compression 400 after some lousy advice. Couple of grand later & he could have just gone & got some REAL heads and been WAY better off :shaking:

The motor is a truck block, 4bolt main, with 202 fuelie heads. It screams, and has never over heated,even on the trail.

I was under the impression that the only 4-bolt 400's were '70 & '71 2-barrel Impala engines.

its the best engine ive had in my 64 chevelle. the kind of torque that ll make your cheeks pucker every time you stab it. o btw yes it runs slightly hotter than my 283, or 350s did. but has never overheated on me. It does have about twice the power though. Buy some aluminum heads if you want good flow. they are getting pretty reasonable. just listen to everybody else and do like i did... drill the heads:)

oh, hey, fordplay....

I know where a set of fenderwell exit headers are for one, too... in case youre puttin it in your toyota.

I've got a ?, I have been told that the 400's won't hold to the higher RPM's that a 350 will due to the stroke difference. Is there anything to this or is this more common misinformation?

the block does have its limits upwards of 650 hp..

I've got a ?, I have been told that the 400's won't hold to the higher RPM's that a 350 will due to the stroke difference. Is there anything to this or is this more common misinformation?


It isn't the stroke that holds the 400 back....it is the horrible rod ratio. Someone correct me if I'm wrong but I believe they have a 5.585 rod? That combined with a 3.75 stroke makes for a sucky 1.48 rod ratio. Not exactly something you want to to be revving. Compare the 5.7 rod in the 350 with the 3.48 stroke and you have a much more reasonable 1.63 ratio which will stay together until a higher rpm. One thing that 1.48 rod ratio does allow for is high piston speed and low dwell which is great for creating some extra port velocity - but worse for higher rpm. I know that you can get some custom pistons to run the 5.7 and 6 inch rods but man is the wrist pin up high. IMO, the deck height is just too low for that stroke if you want to build a high hp piece. From my experience, the 400's seem to work great in low hp, low rpm applications but not so well in high hp situations.

From my experience, the 400's seem to work great in low hp, low rpm applications but not so well in high hp situations.
With out dumping several grand into one, they are like a big block for small blocks.
You can make a 377 out of one and they are more of a high reving engine.


EDIT: btw- where is the 'bacon' option?

people have been known to make 1080 hp without nitrous with an aftermarket block naturally aspirated

David Visard is my favorite engine expert (search ebay for his books) and he loves the 400. You can make 600 hp pretty easily, but the short rod is an issue for power with longevity. You can get eagle and scat rods and cranks in all different combinations for whatever kind of power you want, and cheap too. But since its a truck engine, nothing more than stock or at most a rebuild with 5.7 rods will work great.

My bad, his name is David Vizard:

http://www.amazon.com/How-Build-Horsepower-David-Vizard/dp/0931472245

people have been known to make 1080 hp without nitrous with an aftermarket block naturally aspirated

By no means am I a 400 SBC expert but I would be willing to bet that at 1080 hp with a 400 CI SBC, that aftermarket block has a taller than stock deck height to allow for a longer rod and a piston with a reasonable wrist pin height because I'm sure that engine would be a screamer. A friend of mine who drag races runs a 408 SBC with a 3.80 stroke but the aftermarket block allows for a huge deck height increase that in turn allows for a stout piston and long rod. He is revving in the 9200 - 9500 rpm range and usually sees hp in the 900 - 930 hp range.

short rods make more power then long rods unless the intake is restricted and needs the additional help the dwell of a long rod makes.
every high effort engine will run relatively short rods.
tall decks are for big cubes.
go look at the deck hieght of an NHRA prostock engine. 500" with 9.00" deck hieght. not a real long rod.
IHRA guys with 800"+ use the tall deck blocks to fit a huge stroke, with again a real low rod/stroke ratio.

another example may be found in TransAm (havent followed the sport in a decade so no idea what motors are in it now) where chev started casting 8.2" deck hieght blocks to compete with the fords.
not much room for long rods in an 8.2" deck.

long rods are not the real deal.

Long rods reduce piston side loads and extend engine life. How often are nhra and trans am engines rebuilt? And which would you rather have in a 4x4 truck?

with a 4 inch stroke crank, a 6 inch rod, in a raised cam aftermarket block thats bored 4.155", you get 434 cid.

In an aftermarket block, the raised cam will allow you to run a decent camshaft with a larger base circle than a stock block would allow. If you were to use a stock block, the longer stroke would cause interference problems with the camshaft lobes and rods.

6/4=1.5 rod stroke ratio.
using a standard deck height block, of 9.025 inches, you have the following info to choose from....
9.025 block deck
6 inch rod
4 inch stroke
1.0 inch compression height.

looking at this, you can see that the pistons are going to need buttons and a support on the oil ring. no biggie.

with a flat top piston, a 64 cc chamber head, a 0.25 deck height, and a .041 thickness head gasket *(cometic would be my suggestion here), you would have 11.81:1 compression.

Should run pretty good, considering you get the right camshaft into it.
http://img391.imageshack.us/img391/2058/434mc0.jpg

That's absolute crap you can't raise the cam and 400's are absolute junk








Just kidding... wanted to see if I could give grumpy a heart attack
seriously 400's fuckin rock polls are gay and grumpy knows his shit..... mostly :D

i know a little smelly....


ewwww better wash that finger...



edit: just dont ask me moral/ethical dilemna questions and yer fine.

you can run the 434 in a stock block you just need a small base circle billet cam. $$$$$$$$$

you can run the 434 in a stock block you just need a small base circle billet cam. $$$$$$$$$

you can also run a smaller connecting rod, to get around the base circle issue.
Small journal rods, or honda sized rods would work, but they reduce the strength in the crank, moreso with the honda journal stuff.

If building something this radical, you had better buy some damned good connecting rods with better bolts, like carillos, or something equivalent. its either that, or you can enjoy the view through a new window really soon.

theres some more money... I cant imagine spending 1200 bucks for a set of rods.

everybody has allready spoken all i was gonna say and more but i chime in with a done right they are a Rocken Motor

long rods are not the real deal.

I disagree, they are the real deal for high rpm and reasonable engine life. I'm not certain as to what we are suggesting is a "long" rod? 5.7 - 6.0 isn't exactly long in my book.....I was attempting to point out that the 5.585 rod isn't long enough for making some decent power, IMO.

Some of the race engines you are referring to are not built with the intention of a long service life. Pro Stock is another ball of wax altogether and uses a lot of unconventional parts combos to squeeze the power out. They have absolutely huge flowing heads that rely greatly on piston speed to generate reasonable port velocities. With the limited CI and rpm, a longer rod would slow down piston speed and not draw on those huge heads as well as the shorter rod. Look at the 500" blown hemi stuff.....they just don't care about port velocity or how the piston draws on the head. A 14-71 blower at 120 psi takes care of that. What they need is absolutely max high rpm sustainability without coming apart....they are after the largest rod ratio possible. They want the slowest piston speed and the least cylinder wall loading possible.

I agree with your points on rod ratio.....I also believe that the stock 400 rod ratio is too low. The 400 isn't exactly known for a long service life and there is a good reason for that. There is a better compromise between performance and the life of the short block than a 1.48 rod ratio in a 4x4. Why else is it so popular to stuff the 5.7 and 6.0 rod in the 400? Just my .02, I guess.

you can get a 6 inch rod with a 4 inch stroke... thats a 1.5 ratio...

You can make a 377 out of one and they are more of a high reving engine.


Better still is utilizing a 3.25" stroke & a .030 overbore to get a really screaming 358 ;) Or even a shorter stroke for those drag race classes that penalize weight based on cubes.

In stock form, they are ok. Nothing special. C/R was too low and the cams were mild. There is a ton of potential in one. Put together the right combo of CR, cam, and air/fuel flow and you have a great engine for cheap!

Nobody mentioned clearancing the rod bolts when run with longer rods and a big cam. I have run a 400 for awhile, and I love it. It weighs the same as a small block, but delivers big block power. I run 64cc Sportsman II's with a set of flattops and 6.0 inch rods in my street car.

It weighs the same as a small block, but delivers big block power.


...it is a SBC...........:shaking:.....:D

In modified form it can deliver BB TQ compared to an equally build 350 sbc. Stock cam, comp ratio, and heads made the 400 not so "attractive"...as mentioned already.

...it is a SBC...........:shaking:.....:D

In modified form it can deliver BB TQ compared to an equally build 350 sbc. Stock cam, comp ratio, and heads made the 400 not so "attractive"...as mentioned already.

Thats the point. You get big block power from a small block package.:flipoff2:

you gotta love it.... 40 answers to a one answer question .....:D

hell, there IS a lot of clarification going on, you know.


but, i do agree, it is a one line answer.

I was under the impression that the only 4-bolt 400's were '70 & '71 2-barrel Impala engines.

Speaking of 400's

I have also heard this rumor, and would like to know if it's true. It seemed like a few of my friends had to search pretty hard to find a true 400 with a 4-bolt main...

YES!!! I checked with your friends and the rumor IS true they did have to search pretty hard to find a true 400 with a 4 bolt main... :flipoff2:

YES!!! I checked with your friends and the rumor IS true they did have to search pretty hard to find a true 400 with a 4 bolt main... :flipoff2:

Yep.... I... walked right into that one :shaking:

I've got a 600 hp small block 400 (406) in it. I love this freaking thing I can light up all 4 39.5 boggers no problem. On the street I can smoke most rice rockets and alot of mustangs on my street tires.

Never had any overheating problems whatsoever.