I have a 400 sbc. I have been looking at changing my heads, looking at aluminum, and see where they are talking about not being drilled for steam holes, what gives? Also was looking at upgrading my rockers to 1.6's and noticed there are 2 different shaft sizes, anyone have any idea what stock heads would have? I screwed up, when I looked at the motor I bought, I rode in the car and it had a set of dart2 heads, and it was mean. He gave me a hell of a deal if he kept the heads, but I want it to run better without the expense of puting dart2's back on.
Stock studs were 3/8..the other is 7/16.. The aftermarket heads can be drilled for steam holes at your local engine shop...I do believe most can be drilled, HOWEVER, i would contact the maker just to verify..
i believe the steam holes can be drilled in most iron heads , use a head gasket for a guide. i did it once , but it's been a while...someone correct me if i'm wrong stock rocket studs would be 3/8"
ok , just my 2 cents if i was you i wouldnt get after market small block heads there a dime a dozen for a good set of stock ones 202 or other s . . find a set from somone local and bring them to a good mechine shop and they can build you a sick set . Check cregslist i see them on there every day
first off pull the freeze plugs and clean the water p***ages it is important on the 400s as they have no water p***ages between the cyls. and a lot of gunk builds up in the back corners of the block and cause over heating which is most peoples problem w/400s, 2nd after you buy and rebuild any old 202 heads you will spend just as much as a set of after market heads, world products make a great budget head or on a tight budget a set of vortec heads would work great also, I have gone both routes world and vortec on 2 diff. 400s
some people get ripped off but i pay about 300 for seats cut , valves cut and seals , springs tested ,both heads .how is that more then buying new heads lol ,new heads last i checked are about 700 a side and from what the mechine shop i use tells me there not all that much better and if you read the thread he says he s trying to save money, Just trying to help
I got a 406 sbc in my 40 ford. I used World Products Sportsman II iron heads and drilled them for the steam holes. World gives you instructions in the box on how to do the holes. It sounds hard but is as easy as pie. Ya drill them on a slight angle,not straight in. I think I paid 800 bucks for fully ***embled heads. *****in power right outa the box! I got a fresh set of stock sbc 400 heads in the bag if your interested.
Most heads can be drilled for steam holes, and you can find tech articles on doing it. One set goes straight in, the other on an angle. Can be done on a drill press. Most shops will do it for $50 - $60.
You also have to watch the combustion chamber cc. 400s used a bigger chamber than other small blocks.72 or 76cc heads work with flat top pistons on the street.64cc heads might be a little too much compression for pump gas and a mild street cam. Look in any good catalog[like speedway] for pistons and it will give you compression ratios with different head cc volume.The best deal for the money are the factory iron vortecs, they kill any old style head and cost like $600 a set. Problem is the chamber is small and youll end with over 11 to1 compression ratio.Most aftermarket stuff comes in different cc sizes.Also, buy really good head gaskets, the bores are close on 400s and sealing can be a problem if you build a hotter motor.Fel pro with steel sealing rings work well, the blue ones. Good luck, easy to make an honest 500 hp with good heads on pump gas.
I too used sportsman IIs on a 400 block, took the heads into my old high school shop cl***, and used the Bridgeport mill to drill the angled holes per the directions. Mine was a 377 destroked 400 and it ran hard.
I am in the middle of building a 400. Go buy a set up Iron Eagle Platnum 215cc heads for that 400. They are about $800. That $300 mentioned above to rebuild heads is when you DON'T need parts or any repairs like valve guides (another $150 here for a full set) or exhaust seats (another $100), and a quick surface mill to make sure they are flat ($40). You are at $500 and you now have STOCK heads that are in good shape. You should really upgrade to 1 piece valves is you are going to step on the motor some ($100 for a cheap set), screw in studs (about another $150 to have them installed with guide plates), some new Z28 springs (about $30) and positive seals.... Wow...you are over $800 with a stock head that still flows the same as stock but at least now is built right for being beat on. Or you go and buy aftermarket heads for the same price that flow much better, make more horsepower, and are cast thicker for more durability and porting if you want in the future. You really should go with 1 piece valves (another $100 for cheap ones)
Leave the 202s for some guy who's restoring some Vette or Chevelle. A lot has changed in head design in the last 35 - 40 years.
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