how much hp can a 3970010 block handle. it has high nickel content 010 casting on it. currantly my motor is pushing 515 hp on the dyno with 10.5:1 comp. world 4340, 383 stroker kit, dart pro1 230cc cylinder heads, performance ported, i forget the exact grind of the cam but i have it some where. anyways i wanna up the compression with a piston change and a slightly larger cam, i just don't know what the block will handle. i dont really have the funds for a block swap right now and i don't really want to grout it either cause of other peoples heating problems i've seen. can somebody help out............................................... ....

The only way to tell is when it decides to break on you. There is no definitive answer.

that engine block should just about anything you want to throw at it. i have one in a 1973 that supercharged pushing 650 hp and plan to add even more to it and i am not worried a bit because i build alot of 350 engines for people

You didn't say if it's a 4 bolt block or two botl? If it's a splayed 2 bolt block (with splayed 4 bolt caps) then that is as strong as it gets.

I would be more worried about your rods than I would the block.

its a four bolt block

my rods are forged 4340 as so is my crank.

I wouldn't be worried about taking it to the power level you listed. It should hold up fine.

ive personally run dyno proven 976 hp on a factory 2 bolt block with aftermarket caps and a half fill .biggest problem was keeping head gaskets on, because everything moved so much at those power levels. also had some main cap walk .had to be very careful with tune up not to detonate it .:)

From what I've been able to gather a factory block is usually safe (with good prep, splayed 4 bolt caps, etc) to 600 horse. Have heard of a few that have gone to 700 or more, but it starts getting risky IMO over 600. Somewhere above 600 the factory blocks can split and lift the deck.

The problem is, different castings have subtle differences and even blocks with the same casting numbers are not 100% exactly the same due to date, core shift, over bore, metal fatigue / work hardening, etc.

Sonic checking can help find core shift, plugging the deck, filling the jackets, etc all help, but by the time you get into the expense of all the extra prep work you might as well go to an aftermarket block and not worry about it for a high HP application.

On some of the 010/020 blocks with 2482 center capswe have run 500 those in 500 horse applications and I believe GM rates them at 450 horse but with the splayed caps added we run them up to 600 horse with no problem.

What is the casting date? That will have a very large effect on what the block will handle.

NER perf, I'd like to know a bit about that combo. That's a lot of hp from a 350, no doubt!

I copied this info from a post at HOT ROD, earlier this year. It said that the figures were aquired from SUPER CHEVY, POP HOTRODDING, and some local shops. None completely agreed, so lower values were used and rounded down.

2-bolt w/ OE main bolts = 400hp
2-bolt w/ ARP studs = 550 hp ++high nickel blocks =700hp
4-bolt w/ OE bolts = 475hp
4-bolt w/ ARP studs = 700hp
OEM blocks w/ splayed 4-bolt studs = 950+hp
Bowtie blocks w/ splayed 4-bolt studs = 1500+hp!

RPM plays a larger factor.

OE 2-bolt = 6000 rpm
2- bolt w/ studs = 7000
OE 4-bolt = 7200
4-bolt w/ studs = 8500
Bowtie or OE splayed studs = 8500++

In the article, it stated that a 250hp engine that was spinning at 7500rpm exerted more loading force on the main-caps than a 550hp engine spinning at 5500rpm. this means power and RPM must be considered.

The HP figures are good reference, but the RPM limit of the motor is a better way to choose a block.

So my 383 ci, OE- 010, splayed cap & studs, makes 800hp at the crank. The blower uses 100hp so thats 900 actually being made and I want to spray it with another 100shot N2O. Thats 1000hp at 7000rpm, think it will hold?

I copied this info from a post at HOT ROD, earlier this year. It said that the figures were aquired from SUPER CHEVY, POP HOTRODDING, and some local shops. None completely agreed, so lower values were used and rounded down.

2-bolt w/ OE main bolts = 400hp
2-bolt w/ ARP studs = 550 hp ++high nickel blocks =700hp


WOW this info does not seem very factual. Look in the GM catolog as they have the horse power ratings of what there blocks are good for and i find there info to be very factual.

The customers we do work for are not that stupid to build a 700 horse engine and use a 2 bolt MAINS and I know there will be people say there engine 600 horse and its a 2 bolt block but are basing there info on 1 or 2 engines they have done in there life time.

Here is a good link to read http://www.chevelles.com/forums/showthread.php?t=38173


Here is a pic of a block that came in that was just over 400 horse and it did have studs and studs DO NOT MAKE A CAST CAPS ANY STRONGER AS IT STILL THE SAME MATERIAL.

http://i7.photobucket.com/albums/y276/CNCBLOCKS/flexingcaps006.jpg

Funny any time we have seen this its been a 2 bolt main block and after installing splayed caps the problem goes away.HMMMMMMMMM

Well he already said he cant afford a aftermarket block so its all mute at this point. We had a 383 solid roller putting out 550hp getting sprayed with a 200 shot that lived for years. My personal 377 was about the same and got turned 7800 ( now this did eventually fail, BUT i think the spacers i was using augmented the effects cap distortion at that high RPM ) the 408 thats in my car ( 2 bolt studded ) makes over 600hp and routinely gets driven on the street and sprayed with a 200 shot. Its 3 years old and doin aight.

Point is he only wants to change compression and cam. He'll be looking at what 575hp? He doesnt have the money to try after market block so we are debating all this for nothing. Build it and run it, are you pushing it? yea, but you really have no choice do you.

I agree that RPM plays a big role but USAGE is really key. A 2 bolt 400 HP circle track motor may not live very long at all, where the same HP motor may last for years on the street with occassional strip use. This subject has been discussed ad nauseum here with many differing opinions -- try a search if you want to read a bunch.

Bottom line -- I basically agree with Carl, the difference is that Carl is a builder and seems to do a lot of roundy round motors so he tends to be conservative . . . I'm a cheap skate and tend to push the limits a little ;) Even being a cheap skate, I would never try to get 700 HP out of a factory 4 bolt block with studs and factory caps.

I think that it has been posted somewhere that around 700 hp our regular in a car stock SB block's can split right down the "V"!!

pdq67

ok dudes, i build alot of engines, street performance engines. depending on what i have to work with depends on what kind hp/tq range i will shoot for.
i've never built an all out race motor before so i've never been too worried about block stress. this motor is currantly in my off road race truck where indurance plays a big part cause we drag and slolom at each event. its a 383 stroker that i wanna freshen up for this years season. i race in pro stock and wanna stay there, so the bottle is off limits. we always finnish in the top 3 and this year i want #1. i just found out that i'm going to be a daddy in nov.It's not that I don't have the money for the block, i just cant afford it this year. i'm building a house and got other things i have to do before the baby's born. I'm tellin you this cause i thought it was kinda rude that sombody in this forum is sayin that i have no money and so on. it doesn't really matter i guess. its just a little far off from the question I was asking.
thanx everyone for the imfo.

Well he already said he cant afford a aftermarket block so its all mute at this point. We had a 383 solid roller putting out 550hp getting sprayed with a 200 shot that lived for years. My personal 377 was about the same and got turned 7800 ( now this did eventually fail, BUT i think the spacers i was using augmented the effects cap distortion at that high RPM ) the 408 thats in my car ( 2 bolt studded ) makes over 600hp and routinely gets driven on the street and sprayed with a 200 shot. Its 3 years old and doin aight.

Point is he only wants to change compression and cam. He'll be looking at what 575hp? He doesnt have the money to try after market block so we are debating all this for nothing. Build it and run it, are you pushing it? yea, but you really have no choice do you.

Only compression and cam????????????????what else would you recommend? It's a pro stock motor where the bottle isn't an option. I know my SHI#. I just wanted some input from people who run 600hp or so from a stock block and limitations that's all. I never asked you for your opinion on how much money I have and never planned on this to be a big debate. and my own opinion on this would be yes, with a little work on the bottom 600 is definite. any thing over would be too much of a risk for expensive eternal parts. i just wanted opinions from people who are and have been there.Depending on what i have to work with, i usually build street engines running the 350-500 hp range that fill up at the pumps.

Only compression and cam????????????????what else would you recommend? It's a pro stock motor where the bottle isn't an option. I know my SHI#. I just wanted some input from people who run 600hp or so from a stock block and limitations that's all. I never asked you for your opinion on how much money I have and never planned on this to be a big debate. and my own opinion on this would be yes, with a little work on the bottom 600 is definite. any thing over would be too much of a risk for expensive eternal parts. i just wanted opinions from people who are and have been there.Depending on what i have to work with, i usually build street engines running the 350-500 hp range that fill up at the pumps.

Now you say your an engine builder and just trying to compare apples to apples at your shop what do have for equipment at your shop and being an builder we have a lot of equipment at our shop to do quality work or are you a engine assembler who buys bolt on parts and assembles engines.

REMEMBER JUST TRING TO COMPARE APPLES TO APPLES.

I don't think anybody was commenting on your financial status; just responding to the parameters set out in your original post, "I really don't have funds for a block swap right now".

Apparently, you've already decided that your block is capable of handling 600 HP, so go for it.

apples to apples????????????assembler to builder????????? hey i might not have the balancing equipment, the flow bench, all the neat equipment a good machine shop might have, and hey who ever said anything about myself owning a machine shop. i'll tell you what i do have and that's a nice little garage, lots of tools, i know how engine works and ya know what, I DON'T KNOW EVERYTHING and never claim to, i'm not afraid to ask for opinions, and i may not always get the right answers and i'll be the judge of that. yes i let a local shop do my machine work. and when the jobs done the engine is built right.... and on the dyno, well ****, them apples all taste the same. your own tasting better as always. a builder knows his ****, an assembler compared to a builder is kinda like comparing a father to his son. dont **** on the son cause he may be a father himself.

This is getting outta hand!!

Like I said earlier, I have read where guys have posted that they thought that about 700 hp out of a stock, Car/P/U block, that there is a good chance it will split right down the "V"!!

The 5.0 Blue Oval guys tend to run into this problem more than us Bowtie guys b/c our blocks are a bit bigger and stronger to begin with, but I read that it does happen..

Head and main studs along with a crank girdle and 4-bolt splayed main caps is about the best you can do to help hold one together at these power levels and above, I think??

pdq67

PS., and I do figure a cast-iron intake may, just may, help a bit over a weaker aluminum intake to help keep the "V" from spreading apart, but don't know for sure if one will or not??

thanx for some input. it wasn't intended to get outta hand. i appoligize for myself.

I just bougtht a 69, and its got a NOM 350 block in it and the block cast code is the same, 3970010, it came from either a 79 C-30 or 3500 or an 82 C-20 3500. Its not "hecho in mexico". My question is what type of cam would it have in it? I am guessing a Solid Flat Tappet?? I want to put a pair of Patriot heads on it with a nice matching cam for those, but need to know what type to order. Lemme Know!!! Thanks...