I know you guys get these questions all the time, but I purchased a sbc 400 long block for my 83 trans am. It has two bolt mains. My question is what head/cam/intake combo could I use to wake this engine up. My busget is $4000. I was looking at top end kits to take away the guess work but theyre all for 5.7s. Im told these engines only came with 190 hp. How lame! Any help would be greatly appreciated. Thank you

 

You can wake it up with 5.7 kits. What you do really depends upon what you want out of it. This Vortec head kit http://www.sdparts.com/product/SD806...RPMAirGap.aspx with the RPM intake, Comp XE274-ish cam, 750 Holley, that thing will be very awake.

You will need to drill steam holes in the heads, using a 400 head gasket as a template. But, that's all that would be "special".

 

Awesome. Thank you so much, I appreciate it!

 

Scoogin-Dickey would probably drill the steam holes for you for not a lot of extra money.

When the 400 came out in 1970, it was rated at 265 HP. I was in high school back then, and kept track of what they were offering and what power they made. The '67 327 4-bbl was rated at 275 HP, '68/'69 350 4bbl 300 HP, LT-1 350 at 365, then they started tuning them down. The 400 only had a 2-bbl carb on it.

 

You might want to do some research. I know on some of the aluminum heads they are not drilling the steam holes anymore. I would ask around after you decide which heads you are going to use.

Couple of more things. A lot of the engine builders recommend using heads studs on the 400 engine instead of the bolts. Also be sure that the boring and honing process is done with a torque plate.

 

I wouldn't worry about the holes being there when you get the heads or not. It takes me longer to flip the heads over and put the bit in the drill, than it does to drill the holes. 6 3/16" holes per head. I think it took me longer to type this reply than it does to install the holes.

I would not use head studs on any motor except as a last resort. I have never, NOT EVEN ONCE, seen a motor built with them, that they did not leak. And when they leak, the coolant goes RIGHT DIRECTLY INTO the crankcase. Which isn't a big deal for a race-only motor, with just water in the cooling system; but ABSOLUTELY 100% GUARANTEED FATAL in a street motor with anti-freeze.

Don't bother with whatever stock 400s were "rated" at. It's totally irrelevant.

400s like FLOW. That's ALOT of CID. Remember that the basic SB design was originally designed for 265 CID.

For $4000, you can do ALOT better than Vortec heads. For $2000, it's a different matter. That would also depend on your actual goals, whatever else that $4000 has to cover (exhaust? gears? converter? TRACTION?), the usage of the car, and so on. But for a "budget" build, those heads are hard to beat; and are about all a stock 400 short block will stand, for any length of time. Their limit though, is about 450 HP; which can be easily exceeded with aftermarket heads.

Five7's recommendation of a cam and intake, plus Vortec heads, on a stock 400 short block, is a super easy and cheep recipe for a BIG SMILE on your face. Not a "race car", by any stretch; but a VERY FUN street car. That combo will come close to the 450 HP flow limit of the heads.

 

I believe the reason some builders use head studs on the 400 engine is to cut down the posibility of cylinder wall distortion. It is more of a posibility on the 400 motor than other Chevy small blocks. With cylinder wall distortion you will get blowby and a loss of horsepower.

 

Siamese'd cylinders are about as stable as you can get. Thin walls were a different issue, and studs won't help that.

If you want to stabilize the cylinders, do a half fill of Hard Blok.

 

I'm getting the parts together for a 400 I am building for my 82 Z-28 and I am using the Patriot 215 Super Street heads with Beehive springs, a retro hydraulic roller camshaft with .564"/.574" lift with 1.6 roller rockers and retro hydraulic lifters. I am using an Edelbrock Air Gap RPM intake with a Holley 750 carb. The short block is all stock with studs in the bottom end using the stock crank and rods with ARP bolts throughout. Comprssion should come in around 10:1 with the 64cc heads. Should make great power and even greater torque.

 

I hope that by "ARP bolts throughout" you are including the most fragile part of the bottom end - rod bolts. It sounds like a stout combo, and I would never trust the stock connecting rod bolts in that situation.

 

With Vortec heads and a Lunati cam (230 duration and .480" lift) I'm making 430 hp and 400 ft/lbs. On 91 octane (dished pistons). Build is here:
http://www.chevyhiperformance.com/te...que/index.html

I know chevy high performance then took this same build and used AFR heads, with big chambers and made a 490hp 525 ft/lbs motor that ran on 87 octane. Build is here:
http://www.chevyhiperformance.com/te...ild/index.html

Just some quick thoughts. Good luck.

 

Absolutely, I wouldn't trust any other bolts for the rods. I run ARP throughout my current 355 and I can run that to 6500 rpm's without any worry and that is with the stock crank and stock rods. I've had this motor for about 5 years now and even though I don't have many miles, I do like to put it through its paces.

 

The siamesed cylinders improve cylinder integrity. Going over .030" overbore can make the cylinders too thin. If you're going .040" you'll want to sonic test the cylinder walls for thickness. Going .060" will tend to be too thin.

The heads will need the steam holes but it is the steam holes on the exhaust side that are the most important. Certain heads I've used like an older set of AFR 190's needed to have the steam holes closest to the lifter valley needed to be drilled at a 30* angle. Trust me when I say it's easier to just pay a machinist to do that than to try to do it with a hand drill. Not sure if AFR's still require the 30* for those steam holes. Any of the newer design 190cc heads will run fine as well as the AFR 180. Over 210+ really depends on what you plan on doing and if you're going all out HP.

Head studs aren't necessary but are extra insurance on high HP motors. What you should do is to use deck plugs on the upper 3/4" coolant holes with the cooling holes redrilled to help with deck surface integrity.

The motor I have now is running a hyd. roller with 224 dur @ .50 int & exhaust as well as .540" lift with 1.6 rockers and 112 lsa. Some will say it's small...oh well. Heads are TFS 23* with which we cleaned up further. Ran 11.7's N/A with the 3.27's out back and would actually be able to pass smog if it weren't for the Miniram. Yeah I know it's a little conservative and slow for a 406. Oh well. I did a few other 406 motors with hyd. roller cams with 234/244 dur @ .050 and Lingenfelter 219. Next roller to go in on the next 406 build (when ever I get to that) will probably be along the lines of 225/235 dur @ .050. You can go larger but it really depends on what you plan on doing with your car. Of course you don't have to go roller either. Flat tappet will be fine.

You going carb or fuel injected? If it's going to be a daily street driver, dunno if you want to have a big cam that's going to make power over 2800rpm and peaks out at 6500prm+. Making power high up like that will take some consideration into what you'll have to do with the bottom end. Forget using the stock 5.56" rods. Use pistons that will let you run 5.7" or 6.0" rods. The 5.56" rods just put a little more angular thrust against the cylinder walls.

Just my .02 cents. Take it for what it's worth.

 

My car is nothing more than a weekend toy. I will be running a 750 carb on it since the cost for fuel injection is out my budget this year. I talked to another guy on another forum who builds lots of 400's and he says he has problems running the stock bottom end provided you get the ARP hardware in it and everything checked before assembly. Again, for cost consideration I going to try it and see what happens. Thanks for some for food for thought.