400 chevy build

Anonymous-0

Well-known Member
So what would some of you suggest i build for my 400 chevy. (Cam)? I want to run it on the streets, on high octane pump gas, i want it to have around 375-425 hp, and I want it to be Loud and lopey and have a really rouph idle. Im open for suggestions. Its going in a 1971 nova with a 350 turbo trans and probably a 2500 or 3500 stall converter, the rear will be 3.08 ratio 10bolt with a locking posi unit. Im open for suggestions. thanks- caleb
 
I would look at changing that gear ratio. If I remember loud will come from the exhaust. Lopey will come from a cam that is made for higher rpm power. Why would you want a rough idle? Check out the link and call their tech center this week.
Crane cams
 
Sounds like you want to build something that will not pass a gas station with out pulling in for a fill up. A big cam doesn't do much unless you raise the compression, post and polish the heads, use roller lifters and replace the timing chain with a set of gears. All the takes very deep pockets and to even be able to drive something like that takes deep pocket. Plus at your age insurance will cost you almost as much a year as the engine in the car will cost you. And even after all that a lot of the newer street rods with the high RPM 4 cylinder engines will eat you alive and spit you out there exhaust
Hobby farm
 
You will need a lot more rear or every Honda Civic in Pa will blow your doors off. 3.7s minimum. For the HP you are looking for, look for a a hydraulic equivalent of an LT-1 cam.
Pick up a JEGS catelogue and read through...
A 375HP small block is not a problem- save some engine money and put it into converter and gears
 
Call Doug Herbert performance, (www.dougherbert.com)they have great people, but to get the correct cam for what you want, you will need to know what you have as a base block to start with. Are you going to try to use stock heads and a crank? It would also be cheaper and more durable to get a Ford 9" and hang under it, with a minimm 4.11 gears, If you want a lopey engine, that is a normally a high RPM power band engine, will be a dog tryign to take off with 3.08 gears.I am going into other things on you, but have you got the frame tied together? You try to put 400HP in a stock Nova body, you will twist it. This is just some food for thought, but seriously, call Doug Herbert's place, you tell them what you have, what you want, they will tell you what it will take to do it. Then you know you will have the correct combo, you have to match everything in your engine to get what you want and to keep it together. If you get an incorrect combo, like too high lift cam with dome pistons, first time you hit starter, valves hit pistons and that not good. You going to put NOS on it?
Jim
 
The biggest thing is to have fun with your project .

I do think you would be happier with some lower gears , 3.73"s or so .

Take the time to make sure you have a tight and solid short block . You can change the intake/carb real easily and the heads or cam in a weekend .

Its easy for someone else to tell you how to spend your money on expensive parts . Work with your budget and think about the things you can upgrade on later .
 
If you really want to run good, get your cam custom ground after you have decided on the rest of your engine parts. You're gonna have to lie to the cam grinder and tell him you almost never drive it on the street. If you order from a magazine and use the tech line's opinion, your gonna wind up with a wimpy cam..... I've been there.
 
You're not going to do much with a 400 small block unless you take it all apart and reinvent the wheel. There's nothing horse power about a 400 small block off of an assembly line other than potential...after you take it all apart and realize that you have a large bore small block's block to build from and nothing more, and it had better be 4 bolt main unless you plan to fit (machine) the thicker bulkhead 2 bolt main block with after market 4 bolt caps. Then you'll have to have the mains of a hardened 350 crank welded up and ground down to the larger 400 mains. That will give you a foundation for a 373" stock bore, 378" at .030 over, but you'll still need longer rods and new machined pistons to match the 202 heads you're going to need. And you'll probably need to grind the block to accomondate the better angled but longer rods. At that point, you will have a foundation to work from and build a mouse that roars. 475 HP from a stock 400 with cast low compression pistons, severe rod angles, and a soft nodular crank and scrap rods? Its your money, but unless you start from scratch, you're wasting your money and dreams on a higher HP and higher RPM cam for a low RPM bread and butter engine that won't have a clue or the foundation to support it. And if you do build a mouse that roars...you'll probably detonate that turbo 350 that will no doubt be mated to a rearend geared somewhere between high 2xx and 3xx instead of 4xx or low 5xx at the starting line. And if you do all of that, the gas station guy's gonna love you. Can a screamer be built from a 400's block? Absolutely. Have screamers been built from 400's blocks? Absolutely. But they've been engineered to function with complimenting components to include pressure in fitted rear tires, not by buying a over the counter cam and stall converter from a parts store or mail order.

You'll save a lot of $$$ and a broken heart if you at least start out with a 350, 4 bolt mains.
 
what did you win the lotery or something. have fun affording gas fer that baby! :o me thinks yer nuts. why don't you just fergit the loud and just show tail lights!!
DF in WI
 
The 400 is a great platform, however there are a few things to consider.... The 4 bolt 400"s (early 70"s castings only) were prone to cracking in the main webs. The 2 bolt blocks are more desireable, and they will support more h.p. than people think! A 9.5:1 compression 400 sbc will make 400 h.p. easy! Ask me how I know. It"s all in the top end. They have big bores. The key is to let them breathe! Throw the junk stock heads in the trash. Find Vortec heads in a junk yard, or buy them from Summit, Jegs, or GMPP, or whoever else sells them. Another thing is get rid of the stock rods! They measure 5.56", you wont get much compression with those rods as they will make the piston sit too far down in the bores. Replace with 350 rods that measure 5.7"
 
Im not much of a 400 fan either,,, I had 2 of em,,, in a 83 S-10 shortbed pickup. Started out with a 72 350, then a 355, then a 383 then the 400,, just kept getting bigger ci wise, faster and faster,,, I loved the 383 I liked the 400, but it kept on getting hot,,, had ported out 202 heads, 750 holley double pumper, mechanical secondary, ended up back to a 383,, with 4:56 gears,,,, it would break em loose at 45 mph pretty easy,,,,. But top speed was about 95 mph,,,, but it got to 95 pretty quick,,, LOL! Wish an overdrive could have held up,,,, 373 or a 411 gear, with a taller set of rear tires,,,, will scoot right along too,,, but I sure hope you can drive this nova,,, dont wanna see it, or you wrapped around a tree somewhere either,,,,,

Been fixing up a car Ive had for 16 years now,,,,, never would have thought Id kept it that long,, but its running good! Ford maverick with a 88 roller cam 5.0, fuel injected, just a toy,,,, I got a 71 dogde dart body if any body wants it!!! make a good drag car!! 2 door! has all the glass still in it!! Good project car or parts! I think the AM radio is still in it,,,,, Chad
 
DF in WI,

You must not have had a muscle car in high school.Who cares about gas costs with a bad-A$$ chick magnet like Caleb is buildin'.I like the idea of a kid who wants a REAL muscle car rather than some punk with a turbo Honda(boooo).

I had and STILL have my high school car.'71 Chevelle .040 over 396,Pete Jackson gear drive,TH350,Holley Dominator,Victor intake,MSD ign,411 gears,street-legal slicks,etc,etc.

Farm boys don't always have to drive the pickup to school ya know....
 
well i never did but i had and still have my '91 silverado that has a drop-in 3 fiddy with a holly performance carb and intake manifold with a 5 speed.. never did have a muffler on it when i owned it. it had a cherry bomb on it when i got it but that rusted and i just put straight pipes on it. i only got like 8-10 MPG but it was worth it! the closest thing to a muscle car we had was my mom still has her '83 camaro never really was a bad @$$ car but it was just fun to drive. she likes to keep it all original. i don't know what i'm critisizing for....i wanna find a 67 charger super bee like my dad had! that would be awesome if i could find on!
DF in WI
 
Any reason you keep asking the same questions under four+ names?
You should be seeing a pattern by now. Telling you that you are dreaming if you think the parts you have will build an decent street vehicle.
At age 15 you should have other concerns rather than sinking $25,000 you don't have into a "babe magnet".
 
He never intended to offend anyone and came clean. When you were 15 you'd probably take offence to someone telling you might have the wrong info in a rather harsh way. He deserves some credit for clearing everything up and shouldn't be scared away from the site. If he was older then maybe he could be fed to the lions. Dave
 
Amen to that.A muscle car will woop any ricer on the street and its awesome to be rumbling down the road,instead of souning like a bumble bee buzzing around.
 
Spoken like a seasoned fan of muscle cars. I don't expect it to be your daily driver but a weekend cruiser? Dave
 
Blow some of your money first buying and reading some of those Smokey Yunick books and you'll learn more from those and Chevy performance catalogs than from on here. Check out Super Chevy magazine and advertisers and articles in there too. I never liked the 400 engines as well as 350 and they just seemed to cost more to fix and used more fuel for the power they put out.
 
I just read this a few weeks back. You or different scribe?? The 400 engine was not GM's best bullet. Stick with 350 block easy to find.

Best use of your cash is use it on the down stroke for a newer or a new ride. 3.8 or 4.7 or 5.3 injected will blow the doors off you Nova.
 
By saying he was only looking for some help and and after getting picked on, changed his name to hopefully get some help without being insulted. He his only 15 after all. Most 15 year olds probably would have just left the site. He's got just as much right to be on here as everyone else. Dave
 
Ask about balancing. There is something real tricky about balancing because from the factory, crank, flywheel, and trans are balanced as an assemly. My son and I built one in the 80's but nobody at that time for any reasonable amount of money could balance it. Loads of torque though. Proba bly most I ever saw on anything I drove.
 
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