i just bouth a stock 400 from a buddy and it came out of his old pickup he was using for a tow vehicle

i dont have the money to rebuild it yet but i want to get ridd of the two barrel sittin on top of it i have a plethera of stock sbc intakemanifolds for 350 and 305's so that the plan but wat cfm should i be using

thnx

 

If it's still a stock 400, won't matter much.

Use a stock 4-bbl manifold, and a Holley 6210; 650 CFM spreadbore man sec.

 

A stock 4bbl intake, with a stock q-jet would work pretty good too. Plus you probably have those lying around. You're not giving up any HP with the Q-jet (like the 2bbl!!!)
Then again it's still a stellar 180HP engine.

 

is that really all it has for hp its gota do better than my stock 305 dont it

 

Depends upon which 305 you have.

 

LG4 - yea, barely. It'll be a LOT torquey-er.

An L69? It's a close race. Again, more torque, but the 400 will be lazy. It needs heads and a cam BADLY.

 

well maybe ill just try to sell it then or use the crank for a 383 since i got a nice 350 block

ne ideas on wat its worth never been touched

 

Whoa! Hold the phone guy! It's junk because of heads and cam! Replace those and you have your 425HP fire breather.
You don't just take a good condition 400 and strip the crank out to put into a 350! You use the 400!

 

my questing is how much of a pain is it to have the steam holes put in the heads and if it occures how to take care of the over heating problem they tend to have
not to mention this is a daily driver car before its a race car
so ideas and some more info would be appricated

thnx

 

most machine shops can put steam holes in the heads. don't worry about the daily driver part, these motors were used in a lot of cars and apparently tow vehicles, if your cooling sys. is up to snuff it should be fine for daily driving. just make sure you check for cylinder wall thickness before overboring though. as for carb, a 650 (holley, edelbrock, pick your poison) or a q-jet like said above.

 

Any monkey with an electric drill can put steam holes in the heads.

 

There's no replacement for displacement, go for the 400, I am getting one together for my 82 Z-28 that with any luck will have somewhere about 450-500 hp and the same or more for torque. As for the steam holes, well it is a much debated subject for sure. I go to Nasty Z-28.com and other forums and the consensus is about 50/50 on drilling versus not, and that is professional mehanics as well as do it youselfers. This is one monkey that is having them drilled at my local machine shop since I don't want to take the chance of ruining a set of new aluminum Dart heads.

 

true enough any "monkey" can drill the steam passages, but why chance messing up a set of heads because you dont wanna shell out a few bucks. if it was me i would leave the head drilling to professionals. but that is just me

 

You don't know how trivial it is to drill steam holes. There's virtually zero chance of messing them up.

 

You can hop up that stock 400 for low cost.
What cylinder heads are on it? (casting number)
What cylinder heads do you have laying around? (casting number)
Tell me a bit about the car you'll be using it in.

 

Just ad a set of cheap Vortec heads (that are machined for higher lift cam), and an XE274 CompCam, 1.6 rockers, and the thing will probably do close to 450 HP, and probably have 400 TQ from 2500 to 5000 RPM.

 

sorry but i'm a victim of murphy's law any and every time it can happen, so like i said I would leave it to a machine shop, but to each his own.

 

Wanna build an awesome budget 400ci?

- Vortec heads w/ valve guides machined to handle around .550 valve lift and have the steam holes drilled to match a 400ci head gasket (You HAVE to drill them, or a 400 will overheat all the time, they need the holes)

- Pistons to bring you to around 10:1 CR (they will be dished ones with the 64cc Vortecs and the 400s big 4-1/8" bore)
- Performer RPM intake manifold
- Holley 750 DP (4779) or 750 vac secondary (3310)
- GM HEI ignition w/ vacuum advance and a performance advance curve spring kit
- Comp Cams XE274 camshaft & Comp Pro Magnum roller rockers
- 1-3/4" headers of some sort (Hooker makes a nice set, but they are kinda pricey)

I have a very similar setup on my 350 (different ignition and smaller headers) and it makes right around 400 crank HP. With a 400ci engine, that combo should make a solid 430+HP, a mountain of torque, and be a very reasonable street driver too. Mine was my daily driver for a couple years, it has very decent drivebility and reliability. With a bigger engine, it will have even better driveability and just as reliable as mine.