Want to run on pump gas, if I can find any........here's the info:

sbc 400 bored .040
Com Cam XE268H
Edelbrock Performer mainifold
Edelbrock 600 cfm carb

Budget $500-$800

What combustion chamber size is recommended?
Runner size?
valves: 2.02/1.60
I've read where the heads should be matched to the engine for best performance, don't want to go too small/big.

I was thinking around 74cc with 180cc runner?
Street only, but not a daily driver.

 

Heads should match your displacement/intake/cam. Basically your "power band". It looks like you are building one heck of a torque monster idle-5500rpm so I'd stick with it, something like the edelbrock heads with a small intake runner 170cc.. or trickflows with the larger ports 195cc would sacrifice the lowend which might be a good thing in this case. Both will cost in the 1,000.00 range +/- The trick flows would probably like a bigger intake eventually, something like an rpm or rpm air-gap and a bigger cam. The performer heads would give you insane off-idle response and power with your current combo..

5-800.00 won't get you much of anything except vortec heads or s/r torquers. The vortecs being the better of the two for a 400c.i. because they offer more flow potential down the road and since you'll need a different intake why not step up to a performer rpm vortec.

The S/R torquers are basically a stock replacement head with a beefier casting which will allow more porting than a GM head. Your still stuck with cast iron in this price range tho these heads would work nice with your current combo and some minor porting, the small runners would match the cam/intake well- can you say

I say save up a bit more and get the performer heads, lighter weight, big or small chamber, and a small runner that matches your cam/intake. Then worry about keeping tires on the car.

 

On a 400 you'll need a dished piston to use 64cc heads
and a flat top for typical 76cc heads. For a streetable cr.

What "pump gas" are you planing to use. ( octane)

Here's some recomendations

87 octane 8.5:1 compression 8.9:1 tops

91 octane 9.3:1

92 octane 9.8:1

94 octane 10.3

This is for a cast iron head

Aluminum heads can tolerate about .4 higher cr. ( this is not carved on stone. A motor with 10.7:1 and aluminum heads may detonate on 94 octane. Especially a 400 with its big bore size.

A 400sb build needs accurate cr measurement and planning
and checking to ensure you don;t end up with too much compression for daily driving.
Deck clearance, gasket volume, piston valve relief volume.

If you can't get 94 octane or won't buy it, DON"T don't build the motor with over 10:1. (10.40:1 for aluminum heads) The bigger the engines bore size the more critical and troublesome excessive compression ratio will be. The difference in ultimate power between 9.8:1 and 10.3 is almost irevelevant. The difference in overall daily performance is nill. A 400 has so much more torque than a 350ci motor that you don't need to max out the compression ratio for good performance on the street.
If you're planning on any amount of Nitrous Oxide use now and then, go easy on the cr. You'll be much happier with a little less cr and a little more NOS overall.

I built my 400 with 64cc chamber vortec heads. I had the block "O decked" and use 22cc Dcup pistons, with a for a measured cr of 9.8:1. Runs like a champ on 92-94 octane.

You can also do it with flat top pistons and large chamber heads (76cc) but you need to carefully measure and plan out the final cr . You can adjust the piston deck clearance and head chamber volume to get the cr to an aceptable level. you may need to open up the heads combustion chamber with a die grinder a little to get a good cr. (80cc)

It's easier to start with a D dish piston on this one. Give ya a lot more choices of available cylinder heads.

 

I just grabbed these #'s from jegs/summitracing
vortec- 64cc
performer- 64 or 70cc
world S/R- 67 or 76cc
trickflow- 62 or 72cc

 

Good deal, that's what I was looking for, guess it would have help if I had given you all the info:

Deck: .010
Gasket thickness: bought .041 but can return. Quench?
Piston volume: -8.0 (4VR)

So I'm looking at a 76cc head which would yield about 9.77 CR.
I see some on Ebay, Dart Iron Eagle SS, 76cc/160cc runners, not sure about runners, will check for $700 shipped, What do you think of these heads?

I know the carb and intake are not the best choice but that's what I have now on the 305 that's currently in the car along with the T-5 which I will probably leave in piece's,

Forgot would like to run on 93 Octane, that is if the damn Hurricane's ever go away, I'm in lower Alabama.

Thanks

 

They are a good head for a mild 350. If I was going to buy a head for a 400. especially a new cylinder head I'd look at a 180cc to 200cc head. has more flow, without exessive port volume on a 400 and has room to grow later. a Dart Pro1 180cc head is good out of the box and makes a great head with hand porting. A 200cc version is a good choice too.

The Dart SS head are a nice casting but a little mild for your combo. The extra few $$$ spent on a better head instead of whats available this moment on ebay will pay off well later on.

RHS ( Racing Head Service) (a Comp Cams Co.) has recently bought out Protopline and is relaunching the whole cylinder head product line. Interesting stuff. Lots of choices there too. I like Darts in general ( good quality and performance)
But the 160cc SS head is a better choice for a mild 350 based project.

 

Sounds good, I'm in no hurry, just building this 400 on the side. I'll save up and look around for some Pro1's. Thanks for your time and expertise, just didn't want to screw up and buy something that wouldn't work.