[LouDog]

I am new to this forum and to muscle cars in general. I just purchase a 70 chevelle/malibu in the last month. My question to everyone is....I believe it has a 400 SBC in it. I dont have the capability to look under the car to know exactly...This is what it says on the front of the engine block passenger side of car.

12C405857
T0826CKP

I would like to get around 350 or so horsepower out of her. strictly and cruiser with enough oommphh around town ( I definitely like the muscle car sound too) Without rebuilding the motor. It doesnt smoke and it fires up right away. I was thinking of maybe acheiving that goal with a head/cam combo/ Any suggestion? It has a Edelbrock 600cfm carb and performer intake on it. Some type of headers and HEI ing. I dont have alot of money and I would not be able to do the work myself. SO any information on a reputable shop in Southern California would be great.

Thanks for everyone that can help me. :yes:

 

[trmnatr]

I am new to this forum and to muscle cars in general. I just purchase a 70 chevelle/malibu in the last month. My question to everyone is....I believe it has a 400 SBC in it. I dont have the capability to look under the car to know exactly...This is what it says on the front of the engine block passenger side of car.

12C405857
T0826CKP

I would like to get around 350 or so horsepower out of her. strictly and cruiser with enough oommphh around town ( I definitely like the muscle car sound too) Without rebuilding the motor. It doesnt smoke and it fires up right away. I was thinking of maybe acheiving that goal with a head/cam combo/ Any suggestion? It has a Edelbrock 600cfm carb and performer intake on it. Some type of headers and HEI ing. I dont have alot of money and I would not be able to do the work myself. SO any information on a reputable shop in Southern California would be great.

Thanks for everyone that can help me. :yes:

You could do it by reading and listening here, many have

You also may find a friend on here in your area that may be willing to help you

 

[Highway Star]

Welcome LouDog!! This is the place to learn all about your new ride, and how to get it putting out the power you want. Stick around.

 

[Mike]

That's a 1972 400/170hp from full size car.
Likely has 30cc dished pistons an 76cc heads for a 8.5:1 compression ratio.
64cc heads would bring it up around 9.5:1 cr.
Post the rest of the vehicle info and someone can give you a cam idea.

 

[rich1978]

Hi Lou, the numbers that I know of that you can run will be on the back of the block, passenger side. For example, mine says 330817, which corresponds to a 2 bolt main 400. One you have that number, you can look it up on Mortec here:

http://www.mortec.com/castnum.htm

I haven't had my 400 to the track yet, but I started with a stock 400 shortblock, put a set of vortec heads on (boosts compression) and a 280H cam (230 @ .050, .480" lift), which really idles pretty mildly in a 400, and expect it to run pretty good. May make a little more than 350 horses, but that never hurts right? You could do similarly and run a little less cam and make around 350 with a very mild seeming engine.

Of course, to keep the budget down, you may want to see what kind of heads you've got on it right now. Pull a valve cover, and then look up the number (something like 333882) on the same site I linked above (scroll down to head numbers), post that up and you can get some input on where to go. You can probably take a stock 400, throw a decent cam in it, put a good intake and carb on top and make 350 horses or close with headers. Good luck!

 

[RB69SS396Conv]

That was a 170hp etc. etc. etc.; or, that is the block from such a motor. There's no guarantee that it still is whatever the block was part of when it left the factory. In fact, if I was the betting kind, I'd be willing to bet money it isn't. Could be better, could be worse, but it's CERTAINLY not the same.

The first thing you need to do is to find out what you've got, in as much detail as is practical. Head castings, cam, intake, pistons, etc. DO NOT make the mistake of "assuming" that the block stamping has any relevance whatsoever to whatever is now inside it. Most likely it's been bored and rebuilt, meaning it has new pistons, random heads from who knows where, and probably a copy of the 929 cam that came in it but who knows. About all you can be sure of is, that whatever that stamping code says, is NOT what you have.

Getting 350hp out of a 400 is easy; you can almost do it by accident. The Vortec head suggestion is a good one, although of course far from the only one. But right now it's a great way to go for cheap.

However, I would not, UNDER ANY CIRCUMSTANCES, run a 280H or any other single-pattern cam in a 400 with Vortec heads. Although it's a perfectly good cam, it's THE WRONG THING for Vortec heads at all, and on a large motor in particular. Those heads work by providing all this phenomenal intake flow, since "Vortec" is simply GM-speak for "we moved the intake port up about ¼" toward the valve cover to straighten out the port". But they still have the same sucky exhaust port as about any other stock SBC head; meaning, it's restrictive. You can't get more in until you get the last firing out. Therefore, those heads, MORE THAN ANY OTHERS, respond hugely to split-pattern cams. They NEED the extra duration (not so much the lift) on the exh side, to enable it to keep up with what the int side is capable of delivering.

I notice you mention that you're in So Cal as well. That may impact what you can do to it and still be able to get it through inspection. FIND OUT what the requirements for that car are, specifically the visual part of the inspection, before you spend a dime on anything, lest you find that you threw your money away on something you can't use.

What part of So Cal are you in?

 

[LouDog]

I'm in the San Gabriel Valley Area. And thanks for the quick response. Unfortunately, I don't know much more than what I stated before about the car. As you can tell I am trying not to tear down the car because I dont have the knowledge or time to do so. I am also not trying to build a "400 Street monster" either. You are right it is not safe to assume anything about the car. I am REALLY looking for A reliable mechanic in the area or any recommendation for one.

And could you explain what is meant by "Split Pattern Cam"?

Thanks again

 

[webfoot]

Split pattern means that the duration on the intake and exhaust specs are different, in your case you'd want the exhaust valve to be open longer than the intake lobe, so you would require a cam with more duration on the exhaust side.

 

[cv67]

Wish I had more room in the garage, we could swap cam/heads in a weekend easily. :beers:

 

[LouDog]

Thanks. I know I need all the help I can get.

 

[Guest]

I haven't ran the numbers, but get her up to as close as you can to 10 to 1 CR. so that you can run a bigger cam like a 268/270/272 and install a set of like 190 intake port cc small chamber big valve heads along w/ a cheap set of 1.625" dia., 4-tube, long headers should get you close?? Then you might have to consider a 750 carb??

Please check me here guys!

pdq67

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