halloweenz28

hey guys i know (no replacement for displacement) but it seems like the trend i have been seeing is that the 400's dont really offer the performance expected of 50 ci's more then a 350,

bassically if a 350 and a 400 are both rebuilt like at gennerally the same level wouldnt the 400 beat the hell outta it? but it seems like there are alot of people who dont think the 400 is performance. like 305 sucks 350 is amazing and 400 sucks is this true? should i forget about my 400sb with a t56 fantasy and just get the run of the mill 350

i am a freshman college student and am not rich, but i think ill have just enough dollars to do it, casue the money i have is my savings but i dont have to pay off my loans untill college is over and i should make alot casue im gonna be an engineer. haha so i wanna use my money and do something cool "while im young" haha

also i somewhat know some people who could help me if i need it, and i am also taking an ase engine rebuilding course, (im very good) im rambling so...

recap: is the 400 better then the 350
i want 400 or more tq and 350 or more hp
i could settle for less then that tho

25THRSS

Go with the 400.

cdartz

Get an 87-92 350 roller block and stroke to 383. That's the best way to go if you can afford it.

RB83L69

The 400 is an altogether more powerful motor than a 350, if built properly. As they come in stock trim they suck; but a good set of heads, a big exhaust, etc. will allow one to do its stuff.

Let stupid people think whatever they want; it doesn't affect reality. The people who know what they're doing have made 400s scarce, because they've been buying them all up for round-track racing. If the 350 was a better motor, 400s would be alot more plentiful and easy to come up with in junkyards than they usually are.

heavy_chevy29

the 400sb is an insane torque monster. my 400 was a very mild build up because i was on a tight budget. the motor itself is capable of running high 13s, but my car doesn't hook worth a car. now that i have more money, i can go crazy with it.

i say go with the 400sb. you won't be disappointed

Boomin Boy

i had a 400 in my old malibu wagon which i blew up and switched everything over to a 350.

After doing that i found that the 400 makes a lot more torque, but the 350 made more HP. In the end the 400 was faster but not by much at all.

From what ive read the stock/mild 350 is more stable at higher rpms when compared to the stock/mild 400. Of course if you put a lot of work into the 400 you probably wont have a problem with that anyway. I say go with the 400 for sure. I think im throwing a 406 in my z28 as soon as i do the brakes.

CaddiBird

RB83L69 said it best. 400's are great motors and if given the choice of 350 or 400. I'd take the 400 without giving it a single thought. Speaking of stupid people awhile back I got in a argument with a guy after trying to tell him a 400 crank will not directly drop into a 350 block because the mains are bigger and then theres this other guy who "has" a NASCAR Winston cup engine he got more power out of by puting 305 heads on it.

wesilva

iTrader: (35)

If power is your only concern, add another vote for the 400. If you decide on the 400, go with the 5.7" long rod (or 6") and look into an internally balanced crank. The longer rod will add some life and make the motor run quieter. The internally balanced crank will make flywheel choice a lot easier. Externally balanced 158 tooth flywheels are priced out of this world. Quality externally balanced balancers are pricey too.

unknown_host

iTrader: (1)

The 400 isnt necessarily going to make more horsepower than the 350, but it will make it lower in the RPM range.

That said, a 400 and a 350 with the same compression, same camshaft and same cylinder heads would put out roughly the same amount of horsepower, but the 400 would make it much lower in the rpm range.

Also, a given camshaft (say 235/240@.050 on a 110lsa) is going to seem less streetable in the 350 than in the 400, meaning that the 400 could be built with a larger camshaft than the 350 and in the end make more horsepower with the same street characteristics.

kfoley

Go with the 400, you'll be happy you did. Mild builds put out 450 ponies and 500 ft lbs of tire shredding torque.

MrDude_1

in other words:

you have a bearly streetable 350 making a ton of power
or
you have a milder streetable 400 making the same power.
or
you put a bigger cam/heads/whatever on the 400, make it bearly streetable and be faster then the 350 ever would.

now the question is, define level.
if the level is same heads, cam, ect, then they make close to the same power.. just the 400s is lower in the powerband.

if the level is how streetable it is, the 400 makes more. this level makes sence to me since well... the $300 roller cam im getting will cost $300 if i make it a .200 lift or a .800. i might as well get one matched for my motor. same with everything else... on this level, the 400 will whomp the 350.


i call these people idiots. you have two choices. let them talk and nod your head like its going to fly off.
or my personal favorate.
let them talk, then tell them a forking idiot and heres why. i get some kind of perverse pleasure out of it. *shrug*

no.. its a great dream.... im shootin for it myself

Air_Adam

Inches are your friend... go with the 400" motor. Its got more bore and and a longer stroke than a 350.... its better in every way to a 350 for power making.

Just remember... more inches = more torque, and horespower is a function of torque (torque X rpm / 5252 = horsepower).

The more inches you have, the more torque you will make (all else being equal)... and that means more hp too.

SweetS10v8

Im building a 400 and I think of it this way:

1. Everyone with a 350 seems to want a 383
2. Everyone who has done a 383 seems happy.
3. The reason people go 383 over a 400 is normally 1 of 2 reasons:
a) Lack of 400 blocks
b) They want to keep the factory roller cam block so they dont have to retrofit which is about $1000

4. You can think of it as the 400 is comparable to a 383(same stroke) but its bored .125 already, and its safe! You bet if you could bore a 350 block .125 more safely people would do it to make there 383s into 400/406s

25THRSS

Thank You!!!!!!! This is the most inteligent statement I have heard in a long time on here. Especially, all the guys who think destroking will equate to more performance.:lala:

'84TA w/L69

there is a friend of my family who owns a few gtos...in his main show winning gto...he has a pontiac 400...it makes over 900 hp and torque...but he has over $20,000 in the engine alone...a pontiac 400 is what i want to put into my '84 TA...the only drawback of the 400 is the cooling...they run quite a bit hotter...just make sure you use a good radiator and fan...and maybe some water wetter or 40 below...

cdartz

Those would be my reasons. Lack of money is something I've always had to deal with. I'm not a rich person. My job pays crap. For my last engine swap I bought a used 350 4-bolt roller block that had 57,000 miles on it. I put it in as is. It was clean on the inside with little wear. A 400 would be nice, but I could never afford to do it the way I'd want it. So if/when I'm in the position in the future to do another engine project I'll probably take my current 350 block and make it a 383. After reading some of the comments above I can't help but feel insulted. I do realize that there is more potential with a 400.

And contrary to RB83L69's opinion, I'm not stupid. I'm just not in a position to spend the cash required to build a 400 to my own satisfaction. I still stand behind my original opinion. I think a late model roller block 383 is a better bang for the buck. It does not make me stupid.

MrDude_1

dont be insulted... its ok because you didnt have a choice... now if you chose a 350 on the basis of "i think i'll make more power then the 400 block" then feel insulted... if you just used what you had due to funds, well, thats what hot rodding is about anyway.
we all cant build 9sec street sleepers


then you dont really have a choice anyway.. dont worry about it.



thats part true... while the cost of balancing and putting together a 383 shortblock is about the same as a 400 shortblock, the 383 can take a roller cam, while the 400 needs about $500 more in valve stuffs to be a roller.

but when money isnt a issue and power is, the 400 roller would be a better choice. as you said thats not a option to you, so dont worry about it.

cdartz

Well thanks MrDude_1. You are obviously a wise man.

MrDude_1

you know all that said... i have the parts to make any SBC a solid roller cammed motor...
hence im building a solid roller 400....


my current block turned out to be junk though

but i know where another good one is.. i just have to take a short roadtrip to NC...... next payday...

LilJayV10

iTrader: (5)

I hear ya, there's a guy that comes into work that has a 89GTA with a 350 with 2002 vette heads, with special adapter plate for the headers and TPI intake, he spins it to 9500rpms, took the touqe arm off and put a rubber snubber on top of the rearend to it would stay straight, and he just bout a 500 dollar 4 inch flowmaster system, he keeps breaking transmissions, he had a 5000 dollar TH350 in it, a 4+3 tranny that he got out of an 98 T/A.
You think I'm jokin, the guy has serious problems, he's a habitual liar, he has to be. He said he wanted to race me for 300 bucks, I said fix your tranny and call me.
How people that ignorant make it as long as they do is beyond me.

As far as the 400 goes, I like mine, yes the roller retro fit is expensive. I am going to put a different cam in it this winter I think after I have my heads flowed.