400 Sb

[Bushy]

well im having to have one of the heads in my engine checked out (cracked but sent off to the shop), and just confirmed what i had been suspecting. Ive got a 400 SB instead of a 350 !! woo-hoo! so im gonna go ahead and put a carb and manifold on it. any suggestions as to make, type ? im all ears, as i have very little experience with this engine.

[ozarkhippie]

Did you not look at the harmonic balancer and see if it had the notch in it that the 400's have.

[68 Suburban]

Make sure those heads have the proper steam holes.

[Bushy]

Uh, That would be a no. Excuse my ignorance, what is a harmonic balancer ? I haven't even heard of that. Is it related to a johnson rod ? (lol,seinfeld reference)

[ozarkhippie]

Yeah it connects right to it

[bobclem]

I have the same engine with Edelbrock intake and carb,wow what a great way to go, put some headman headers on it also. Good luck CHEVY ROCKS

[bumpster]

Don't forget the flywheel is different , not just the harmonic balancer.

[47Firetruck]

The harmonic balancer is real!! It's on the end of the crank shaft. It's what the bottom set of pullies are bolted to, middle, bottom of block. 400s are exturnelly (sp) balanced via the ballancer and the flywheel. Or at least that's what I've been told. Of course I could have that back ward and they are internaly ballance so some one correct me if I got them confused. Just make sure you use 400 balancers and flywheels.

[trinic]

i think you do have them back wards...

[47Firetruck]

trinic

Thanks for correcting me! Was wondering if I had them swapped.

[Bushy]

Any suggestions on Carbs, Manifolds Distributor cap ignition module etc. for this monster ? Just checked the numbers and its out of a 72 chevelle or monte carlo.

[mikej71]

47Firetruck was right - the SB400 is externally balanced. A 350 is internally balanced.

Mike

[dinnut]

a lot of people use the ever popular edelbrock performer intake and 1406 600 cfm electric choke edelbrock carb.

im going to be running a performer rpm with a holley 600.

[lukecp]

Get rid of that 2bbl!

Anyway....i would reccomend an Edelbrock Performer intake (#2101) and Performer 600cfm electric choke 4bbl carb (#1406). Should be a huge upgrade over that 2bbl.
You may want to try out a Performer EPS Intake too...

Also, i can't tell by the picture, but if you are still running a points distributor i would highly reccomend an HEI distributor. Easily available at any junkyard and should improve starting, MPG, and power.

For the headers....get the best you can afford.

[Bushy]

Thanks for the advice dinnut and custom! I was leaning towards edelbrock components and barring the guys fom Hot Rod Barn convincing me otherwise ill probably go performer series. Im still debating 600-750 cfm, but ill figure that out. Basically, if im gonna leave the block alone after im done with the repairs, i'll go 600. But...I'am such a mod-aholic i know its only a matter of time till a cam valves heads etc. enter the picture, in which case i'ld definently lean towards the 750. The performer eps manifold looks rad, i would love to use that one i just have to make sure it will work with air conditioning,etc. I'm also going to do all ignition/ spark stuff at this time too. Man the guys at the Barn are going to LOVE me!

[1972C10]

Performer RPM is a good intake to look at .

But it does work better with a cam of 450 lift 250 duration or better

The performer 2101 is A good intake to use with a stock or mild cam I dont know if i was in your place if i would use the rpm without a cam swap .


Carbs are carbs 650 would be a good size but a 600 would work nice too. Edelbrocks or holleys all a matter of personal preference and tunig ability

the holley is a more perfomance based carb IMO, but requires more upkeep than an edelbrock

[Bowtie67]

Holley Stealth Ram, or Holley MPFI, Switching over to Holley Stealth Ram on my 414SBC this year, I have run the Holley MPFI on a 350HiPo and now I will never look back to having to screw with carbs again. Definately better MPG and personally I think much better drivability. I still have the Holley MPFI setup with manuals, Software, Complete Wiring and all, Priced to sell.(not giving it away) Also set of Edelbrock RPM Heads with less than 10k on them

[Blue_71]

if your going to stay carbed i'd like to recomend a REAL carb, holley 4160 or 4175. i absolutly HATE edelbrocks, they do not agree with me at all.... the edelbrock on the 74 starts easier and runs okay when it gets warm, but the 2 barrel had more umph to it (it also had to be warm, and it still had points when it had the 2 barrel, now completly rebuilt HEI)... ive tried 2 edelbrocks on my K20, they wont even fire, i can take them back off and bolt on my holley 4160, and it starts first couple of turns

[MAC67]

little more bucks but wow i really like em , the performer rpm AIRGAP , and a 600 or so , that is a nice intake ,, probably want a little more motor tho , if youre gonna leave her stock id just run the regular performer ,, go wild keep the 2 bbl and add a couple more with a 3 duece setup ,, thatd be neat on one of these trucks, edelbrock makes the intake

[Longhorn Man]

The air gap doesn't really do too much in a close engine compartment. The whole theory of cool air surrounding the intake manifold doesn't really hold much water.
I would go with an Edelbrock Performer RPM and performer 750 w/electric choke.

[MAC67]

i dunno long horn , 95% of the enines ive had them on made a serious change for the better,, i thought the same as you ,, i thought of it as another imo K&N scam , i dont think those things are what they say ,, i sure dont think an aircleaner is gonna flow enough to add 15 hp , hell i wonder if i run witout an air cleaner it oughta bump it about 30 hp then right ? im just talkin from expieriance here

[fast71]

Hey Bushy ,What part of Tennessee are you from? Also Are you sure that is a 400 sbc? the intake is a 307 . I see that someone has changed a few thing like the brackets so its poss. they put a 307 intake on a 400 . check the numbers on the back of the block or just post them someone will check them for ya. or look at the balancer (see pic) or look at the side of the block some 400's had 3 freeze plugs instead of 2.

[Hooter]

just make sure you get those steam holes drilled out, or youll keep cracking heads, 400's are famous for that

[Bushy]

yeah im positive its a 400, bore is the same and engine block #s are from a 72 chevelle. Someone dropped it in, when i have no idea. They obviously dropped it in for a little more juice (maybe they were lucky enogh to have a 400 lying around) but why they put on that restrictive as* carb and manifold is a mystery to me. however they also disconnected the factory air and heater as well even though all of the components work fine (minus compressor of course, couldn't be that easy). Thats what got me started on this whole project to begin with, got tired of freezing to death every morning! Fast71 i'm in knoxville,Tn. Also im curious, most of the rpm manifolds ive looked at use dual carb set ups, is there one that is a single and also works w/factory air, i'ld love one but apparently havent found one on summitracing.com yet. whoo, that oughtta do it (typing on a tiny notebook keyboard is fun!)

[FRENCHBLUE72]

Just my 2 cent's worth but you may want to look into getting the whole edelbrock package if you can swing the $$$$$