Im about to build my first chevy motor ( 400 small block). What kind of heads and intake would be good for lets say more than stock but not a drag strip motor? Im putting it in an 86 GMC pickup, and should i use flat top pistons?Ive heard flat top pistons would blow out head gaskets. Any info would be helpful.  

Most bang for the buck is Vortec heads, these require a unique intake to bolt up to them. GMPP, Edlebrock, Holley and others supply intakes for either carburetor or injection engines with vortec heads. These will deliver 40 hp over early "power pack" heads and 60 to 80 over open chamber SMOG heads, the kind 400's came with.

The 400 block requires that non 400 heads be drilled in 6 places to pass coolant around the siamised cylinders. This is easily done follow these instructions:  

The Feb. 03 issue of CHP has a how to article called "The 400 Drill" with pictures I don't have nor can find a URL to this any more, the guts are below.

Basically you do six holes per head, use the 400 head gasket as a guide. There are 3 outboard (toward the exhaust side of the head) and 3 inboard (toward the intake side of the head).

The three outboard (exhaust side) are drilled straight into the water passage at 90 degrees to the deck surface. The three inboard holes (intake side) are drilled at 30 to 45 degrees to the deck surface angled toward the exhaust side of the head. You only drill till you penetrate into the water passage. This lets coolant pass from either side of the siamesed cylinder walls into the cooling passages of the head preventing the formation of a pocket of non heat conductive gas (steam) under the head deck.

Use a sharp drill, new if you doubt your sharpening abilities. Use a good quality center punch and place a punch mark where each hole will be drilled to prevent the bit from wandering off on to the machined surface. A 1/8th to 3/16s inch hole is perfectly adequate; no chamfering is required, nor desirable. The edges of each hole need to be lightly deburred to insure there are no raised or sharp edges that could compromise sealing.

For pistons, flat tops offer the best detonation resistance but with the Vortec 64 cc chamber the compressions too high for street gas. The other best 
choice is a "D" dish or cupped piston such as the Kieth Black, Silvolite KB126 with a 22 CC cup or KB 130 with an 18cc cup. see http://kb-silvolite.com/performance.php?action=start

There are some other selections as well pay attention to the ring thickness and tension. Racing uses a thin low tension ring, this does not work well on the street where you want the thicker and higher tensioned rings. These pistons are listed with pin retention rings, this is for competition engines where the pin floats in the rod. For the street a factory press fit is fine and the pin that comes with these pistons accomplishes that without the use og the retention rings.

The Vortec and other fastburn heads depend upon a tight closure between the piston and the quench deck of the head. This squirts the mixture into the valve pocket side of the head with great force causing great mixing and turbulance which results in a faster moving flame front. It also provides an zone on the far side of the chamber with a high surface to volume ratio, this reduces the end burn temperature which is a major cause of detonation. These two features permit considerable compression to be used with unleaded fuels which was not possible to achieve with older chambers. The intake ports of the Vortecs are better positioned and shaped, modeled after the reverse cooled LT-1 heads. These ports offer much improved mixture flow without resorting to large ports with slow moving mixture, which are rather sluggish except at red line RPMs. The Vortecs on the other hand offer all the high speed advantages with lots of bottom end grunt.

Piston choice of cup size 30 or 18 cc will have to be made after selecting the head gasket thickness. Static compression depends on the formula derived from the following volumes:

(cylinder swept volume + head gasket thickness + deck heigth + combustion chamber + piston cup)/( head gasket thickness + deck height + combustion chamber + piston cup)

Bogie  

All great advice.  400's can be tricky when it comes to streetable compression.  I would bet the pistons are going to have to be closer to 30 cc dish with 64 cc chambers to keep it streetable and on cheap pump gas.  The Vortec heads do have a great combustion chamber and due tend to like less ignition lead than other heads, which are benifites.  If I recall correctly, the pistons for my 406 are around 18cc dish (don't remember off hand) and will be close to 11:1 with a 64 cc head at zero deck (also don't recall the gasket compressed volume off hand).  Use Bogie's advice and keep an eye on the compression and I think you'll be happy.

Are the World Products S/R Torquers comparable to the Vortecs in performance?  

The Vortec heads are better than the SR heads.  The Vortec heads will flow better and have a better combustion chamber design.  That being said, the SR heads aren't bad.  They are 170cc intake runner (same as the Vortec) and come in either 58, 67 or 76 cc combustion chamber and can come with 2.02/1.6 or 1.94/1.5 valves (Vortec heads have 1.94/1.5).  But, as the name implies (SR=Stock Replacement), they are limited.  Vortec heads would be a better choice than even a 2.02/1.6 valve set of SR Torquer heads.  More bang for the buck.  My opinion.

Thanks for the reply.  I was considering the vortecs , Torquers or a set of darts.  Either way it seems I will be out of the same amount of cash.  WIth the vortecs I need a new intake and need to have stiffer springs installed.  But if for that same amount the vortecs perform better I will get them.  

The 30cc D-dish pistons with a .005 deck height and vortec heads will give you about 9:1 compression.  You can probably run the cheap gas with that combo.  

chp website is a welth check out this atrical

http://chevyhiperformance.com/techarticles/148_0306_406/

Summit also sells a set of their own Vortec heads for 325 a piece that already have stiffer springs.  There part number is sum-151124. Anyone know if these will accept standard rockers and push rods.  I called their tech support and the guy could only read me the same description that I saw online.  

when I ordered my vortec's from scoggin-####,  I got them with the z-28 springs (which aren't good for much over .480)  they were macined for screw in studs and guidplates( and they were installed)  It cost a little extra but it was well worth it.  I ended up taking them to a machine shop to have the spring pockets enlarged for a bigger spring, I ran a .560 solid lift cam on them with an edelbrock performer rpm valve spring.

ha ha they edited #### haha  they're website is sdpc2000.com

I've recently finished a 406 with Vortec heads and am nearing 1000 miles on it in a '76 Blazer.  I'm very happy with the engine.  A couple of things worth mentioning though:

Vortec heads have no exhaust heat cross-over provision - this may not seem like a big deal but it is on cold/damp mornings.  The Edelbrok Performer RPM intake has provision to run engine coolant under the plenum as a substitute for the missing exhaust heat.  The standard Performer and the Performer RPM Air-Gap do not.  Depending on where you live, this could be a big deal (I'm in Portland, OR and it was a very big deal for me as the truck barely ran without the coolant cross-over hooked up).  Getting fittings that work isn't as easy as you'd think either.  The tapped holes for the cross-over are very close to the plenum so 90 degree fittings won't thread in.  The throttle linkage usually prevents a straight fitting on the driver's side.  I used Aeroquip 45 degree AN to Pipe fittings in the manifold and Aeroquip 45 degree hose connectors to accomplish the necessary 90 degree bend.  It just fit's under the throttle linkage of an Edelbrock carb with a standard gasket.  Pretty damn expensive but a very sano installation.  Of course, a thick carb gasket or carb spacer will provide additional clearance as well. 

Apparently the exhaust mating surface is at a slightly different angle than early heads.  My brand-new set of Hedman Elite Series headers would not bolt in.  There was interference with the frame rails on both sides.  I notched the frame rails for clearance.  Worth thinking about for your application.

Brackets:  factory brackets from early model engines don't seem to work with the Vortec head setup.  I used an aftermarket alternator bracket intended for street rods which seems to be doing well.  The factory transmission kick-down brakcet originally bolted on with the intake mounting bolts.  These bolts are at a different angle and spacing on the Vortec heads.  I haven't fabbed one up yet (so no auto kick-down when I step on it).  I purchased the Edelbrock Universal bracket for Vortec Heads but it would either work for the throttle return OR the kick-down - not both at the same time.  Additionally, the mounting flange interferes with the rocker covers so it couldn't simply be bolted on using the intake mounting bolts.  I had to replace the two rear mounting bolts with studs so I could elevate the bracket base for clearance from the rocker covers.  All that and it didn't even work.

OM Gang

He can go here to Sivilote's for a calculator  http://kb-silvolite.com/calc.php?action=piston  . To get a 9.5 for example with a stock bore of 4.1253 and stroke of 3.75. a .020 thick gasket of 4.2 inch bore, a deck clearance of .020 inch, and a 64 cc combustion chamber; the calculator comes back with a nearly a 24 cc dish.

He also needs to shop by rod length as this affects the pin position in the piston, which in turn affecs how high the piston crown sets in the bore at TDC. So selections of dish volume will be limited by rod length, the stock rod of 5.565 inch has the fewest choices which tend to be small (7-12cc) which will generate way too much compression with Vortec heads.

Bogie

Great information.  Thanks.  Sorry for the delayed response.  I don't always keep up.

I haven't seen a piston with that much of a dish.  24cc is a little smaller than I would have thought it would have to be, but still in the area.  Seems like that would be a pretty good size dish in those pistons.  I guess trying to stay with a d-dish would at least help keep the quench?

There is a 30cc D-dish KB piston - It's what I'm running in my 406

Summit part#   UEM-KB126030-8

OM Gang

That's what I hear.  I just haven't physically seen one yet, so just trying to picture a dish that big.  Almost half the volume of the combustion chamber.  Pretty cool.