Ok, here is another, what parts should i get, question. I have a 2 bolt 400 block, im not sure of the casting #'s right this moment. And a set of good, bare 882 heads to start with. The block is bored 30 over and ready to go. So im looking for all the parts. I dont have a HP number in mind, i just want to get a decent power motor for a limited budget, and stick with my holley TBI if possible. So everyone put your minds together, and see what you come up with for me for some major parts, part #s would also be nice. Thanks guys!

 

Anchor the 882 at the bottem of the lake and then we will talk about building a 400.

 

Ah, come one, those heads cant be that bad, i got them at a swap meet for $25, i think i can get the local machine shop to do them up right for me, what heads would you recommend? And lets star talking 400's

 

They're not that bad, they're much, much worse than that.

 

i guess what im really looking for would be suggestions on cranks, pistons, cams, rockers, push rods, all that good stuff

 

cheap 400, lets see.

scat crank, scat 5.7 rods and and generic flat top pistons will do fine. iv used kieth black and several other brands and could not tell a difference. flat tops are flat tops hahaha. if you start going more than 10:1 flatops thats a different story. you gotta order special pistons if you go to the 5.7 rod (350 rod) i went with the 5.7 rod to lesson the (eggshape affect) the short 400 rods are known for. also the piston stays at the top longer if you have a taller rod, but not by much. i had to grind the corners off my rods and re weighed them because they hit the camshaft. but im running over .550 lift though. there is a special small diamater cam you can go with but its expensive of you want a really huge cam. but if your going to run stock heads i would not go over .500 lift on your cam. mine started snapping the stock valve springs at 40k on the engine and i only had .480 lift. iv never used stock heads since hahahaha.

also i ordered the cheapest crank and rods scat sold and i rev mine out to 7600 rpm all the time. so they do hold up, but if your stock crank is fine and it checks out ok use it if you want. and plus if you use the stock rods you dont haft to grind and re weigh. but those scat cranks are really cheap. iv had good luck with them. and the stock rods, iv never put more than 450 horse on the stock rods. but thats just my preferance hahaha.

if its going to be a daily driver just putting a 400 in it alone is going to fun. there weakness is the rods mostly and the stock 400 heads suck, and your "supposed to" drill the heads for the steam ports if you use anything other than a 400 head. iv always done it. but if you buy heads with no holes and you have them drilled it usually voids the warrenty. thats about it. other than that its just like any other engine. i only built 400s with a powerglide behind it. never built anything else. not even a 350 or 305. and iv never built a stroker iether. why have the stroke when you can have the bore to hahaha. i might someday. but iv beat allot of folks just messin around on the street with the 400. there torky from the get-go.

 

If you're on a budget, it doesn't matter much what you use. You could use a stock crank, stock rods (5.7 preferrably, or 5.565), hypereutectic pistons (watch the compression ratio). Rockers, pushrods, etc. are even less important, they're the same as on any other SBC.

But it doesn't matter what you put in if you're going to use 882 heads. They're a big part of the reason a stock 400 made about 140 HP. If you use those, you're going to get a dog.

 

Might want to double check and see what kind of crank you have. A lot of 400's came with forged cranks (more so than 350's).

As for heads you are going to have almost as much $$ in rebuilding stock heads as you would in a set of vortecs. A vortec 400 with a 220 somthin cam would easily make 375 hp if not 400. You'll be running bottom 13's or even 12's.

 

I dont have a crank, this is a bare block, nothing came with it. So i can put whatever crank in it and all the other goodies. As far as the heads, if im looking for a good set of heads, what sort of casting numbers should i be looking for?

 

Vortecs (062s or similar) with whatever mods are needed to make them work properly on a 400 would be a good way to go. Id get a set of castings and have them machined for larger springs and screw in studs. Also wouldn't be a bad idea to give them a once over to clean up the ports. Theres some room for improvement there as there is likely some core shift and casting flash in the ports. Might also be a good idea to put in larger exhaust valves as well. What ever you do, don't use a set of unmolested smog heads on it. With a lot of displacement, you need good flow at the heads and a decent cam to go with them.

 

Listen to what everybody is telling you.

THROW THOSE HEADS IN THE TRASH!!!!
You don't have "heads", all you have is 882s. "Head shaped objects".

Then, go get yourself a stock crank, stock rods, and stock replacement pistons from TRW or some such. Or, one of the "kits" you see everywhere, with a cast crank and low-$$$ pistons. Don't waste your time, effort, or money on the bottom end. TBI will protect that from EVER being an issue. Concentrate on getting good heads. The HEADS are where power lives.

Vortec heads (906 or 062) are probably the cheapest best way to go, since you have nothing whatsoever that's useable now. Unfortunately you'll need an intake too; but they're cheap. Any decent 4-barrel carb intake for Vortec heads, plus a TBI adapter, will do fine. A Performer RPM is probably the best cheeeep way to go. A Comp XE262 cam would be perfect with the rest of that, shouldn't even need all that much chip work, if you get yourself a set of 454 injectors.

 

My setup

400 w/ dished pistons
stock vortec heads (I bought some replacement "Z28" valve springs)
A lunati cam 230 duration and .480 lift
stock rocker arms
a holley 700 dp
knock off air gap intake

I've ran 12.8 with this setup. I'm sure it will go 11's on nitrous and prolly hit mid 12's with an electric water pump, roller rockers, and some suspension work. In chevy high performance this setup made 430hp and 525ft/lbs of torque. Runs on 91 octane.

My 400 had 882's and an edelbrock cam before I went to the vortec/lunati combo. I can tell you that the 400 small block with 882 heads and edelbrock cam combo wasn't much faster than my 305 (which had edelbrock intake and carb, hooker headers)

 

Sounds similar to mine:

4-bolt straight mains 400 block .040 over
dished pistons
stock crank/rods
lunati 60103 (forget the numbers)
performer rpm intake

I hope to get a good set of heads and run a demon 750 or similar carb on it. I was gonna stick the crappy wedge heads that came with it on it when it went into my RS sadly it was totalled by some idiot in a pickup so now I have a little time to get some good heads while I find a nice home for it.


The general rule for mains as I was told was 2-bolt will hold 400hp, 4-bolt straight will hold 500hp, and a 4-bolt splayed will hold 600hp+. I went with the stock crank and rods as I don't plan to spin the motor very high but go for more of a street thumper as I plan on having it in a manual car (either TKO or T56).

 

On a 400 the four bolt main is weaker than the two bolt.

 

Those numbers get quoted a lot, but the fact is there are a lot of 2 bolt blocks that make more than 400 HP, just like there are lots of dead 4 bolt blocks that make less than 500 HP. Block condition has a lot more to do with the suitability for HP use than how many bolts are holding the main caps on. If you're planning on building something that can be driven on the street, either is fine.

 

Sounds like an old wives tale to me, do you have specifics to back this statement up?

Apeiron, I agree completely. Also how high you plan on spinning the engine will factor in to that also. I'm not worried either way as mine will just be a low-end street monster.

 

The 4 bolt 400 blocks (and early 2 bolts) are a lighter-weight casting with less material in the main webs.

 

If you look at a 4-bolt block and a 2-bolt one side by side, it's kind of obvious what the difference is.

It has NOTHING WHATSOEVER to do with 4 bolts vs 2. It just happens though, that the early ones got 4-bolt caps put on them, where the later ones got 2-bolt ones.

The earlier blocks simply had less metal in the main webbing area than the late ones had. Consequently the main caps and therefore the crank, aren't as stable. Starts to show up around 6700 RPM and/or about 550-600 HP. The 4-bolt blocks tend to have more "cap walk" under severe abuse like that.

Does it make a difference for a street motor, that's going to have a TBI on it? I highly doubt it.

 

If you lay a 2-bolt cap and a 4 bolt cap side by side, especially a 400 cap that has larger diameter mains, it is apparant that the main cap itself is weaker on a 4-bolt main. The area on the caps immediately surrounding the step between the bolts is THIN on a factory 4-bolt main cap, MUCH thinner than a stock 4-bolt main cap 305 or 350. In fact, I once pulled apart a good running STOCK 400 SBC that the 4-bolt main cap came off in two pieces. The Main Caps themself are known to crack into two pieces. A factory 2 bolt main block splayed to 4 bolt mains is MUCH stronger than a factory 4 bolt main anyway.

 

was going to post what fast said. ive had 2 of my 4 bolt blocks(more than 1)break the thrust bearing cap and the one forward of it. you can buy a 421 stroker rotating assembly, already balanced i believe, from powerhouse or one of those circle track vendors. some patriot performance "large port" aluminum vortec heads and youd be good to go.maybe open the chambers up to improve the valve unshrouding and possibly lower the compression by a point(maybe) i would specify a dished blower type of piston to lower dynamic compression and keep your piston to head clearance around .045 with a .005 deck height so as not to lose quench. top rpm around 5700. more than 400 lb ft from 2000 up to about 4500. horsepower in the mid 400's me thinks

 

Well it's a given that any splayed main with be stronger than a straight variant. I did not know about the 4-bolt 400s having less material in the webbing area, but as stated it shouldn't be a deter of any kind on a street engine.

 

wow every one is hateing the 882 heads. whats so bad about them? i have a set of 73' 882 castings on my 350 and they dont seem too bad but i am goin to up grade them

 

They're low flow, low compression 70s emissions heads that on top of their nearly zero performance potential are also prone to cracking due to their "lightweight" design.