is this possible? 340 build any help would be appreicated.

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1969 s conv

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ive got a 69 stock 340, my question is this. can i build a 425 hp motor with out boring the block? ive got factory stock exhaust manifold which i would like to get bored out if possible. the car has he stock carter carb so i would want to retain it looking stock but have a bit more punch. ive read the stock motros put out 325hp so is it possible to get another 100hp? i thinking i would need to do some head work and cams any idea on that? thanks dave
 
425hp through the stock manifolds and carb, standard bore, non stroked? That power at the wheels, I assume.

I say no..... With this side note: Even if you did hit that 425hp number the engine would be at a state of tune that would not be practical for street use.
 
Can it be done, Sure but it will cost you and wont be practical. You would be better off with a 4 or 4.25" stroker crank, You will need to port the heads to feed it also

This car looks 100% stock under the hood and runs 11.40s
 

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how is that car possible? now if i bore the block it will take away value of the car correct? i'm looking to get more hp but not a cost of taking way the value of the car. i own a # matching 69 barracuda conv formula s auto.
 
In that case don't build the original engine. Go get a late 80s 360 roller motor (pre mag) and build the hell out of it. This way if you blow the thing up you won't have to worry about it being the original motor. Also post some pics of your car.
 
boring the block is part of rebuilding the motor. It wont take away from the value. I would find another block and set of heads to build and just use your intake carb and exhaust manifolds.

The car picture uses a 360 block with a 4.25" stroker crank. Its 444 cubic inches, It has a stock 72 340 iron intake, stock 340 exhaust manifolds and a carter thermquad,
 

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So you think boring the exhaust manifolds won't hurt it's value but boring the cylinders will? Ring seal is paramount to making good horsepower out of any combo.
 
i need to take some new pix of the car. right now there's nothing special about it. ive owned the car since 89 and its been sitting in a garage since 91, but i will try and get some pix up tho.
 
Go get a roller block, best way to go about it
 
1969 s conv said:
ive got a 69 stock 340, my question is this. can i build a 425 hp motor with out boring the block? ive got factory stock exhaust manifold which i would like to get bored out if possible. the car has he stock carter carb so i would want to retain it looking stock but have a bit more punch. ive read the stock motros put out 325hp so is it possible to get another 100hp? i thinking i would need to do some head work and cams any idea on that? thanks dave
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Let me convolute your question a little. With a stock bore 340, properly prepared heads and well thought out parts the answer is yes. 425 flywheel horsepower is entirely possible. You would be running headers, not manifolds.
 
The car picture uses a 360 block with a 4.25" stroker crank. Its 444 cubic inches, It has a stock 72 340 iron intake, stock 340 exhaust manifolds and a carter thermquad,
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you forgot: the car has had weight taken out of it anywhere possible, big $$$$$ into the heads intake manifolds and internals of the engine thats no $5000 rebuild thats for sure, big bucks into the trans i'm sure its light weight everything inside and then the rear probably has some not so street friendly gear in it, it may have traction control and go knows what other big dollar tricks they do to those things to get them to run 11's looking stock..
 
Out of curiosity... Why "425hp"?
I'd be more concerned about welding metal under the body to keep the doors closing normally. Considering the amount of twist the Duster shows... how bad do you think the body will twist with no additional reinforcement and no roof?
 
abodyjoe said:
you forgot: the car has had weight taken out of it anywhere possible, big $$$$$ into the heads intake manifolds and internals of the engine thats no $5000 rebuild thats for sure, big bucks into the trans i'm sure its light weight everything inside and then the rear probably has some not so street friendly gear in it, it may have traction control and go knows what other big dollar tricks they do to those things to get them to run 11's looking stock..
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I never said he only wanted to spend $5000, he asked if it was possible.

I dont believe Chris ever touched the intake or exhaust manifolds, Yes the heads have a lot of money in them and the car was lightened, No heat, radio ect.

The car has 373 gears and a spool and I believe Chris built the 904 himself with a T/A reverse manual valvebody (on the column) and a 3000 rpm converter.

The car did have a lot of compression though, around 13.5"

Obviously a set of hearders and edelbrock heads and intake would be the cheap easy way to more power but that wasnt what he asked.
 
Get yourself some headers,save your logs for later. Get a good single plane M1 intake, 850 carb, and Edelbrock heads. Cam to HP levels per cam manufacturer help line. 425 is possible but it moves you out of streetablilty pretty fast.
 
pishta said:
Get yourself some headers,save your logs for later. Get a good single plane M1 intake, 850 carb, and Edelbrock heads. Cam to HP levels per cam manufacturer help line. 425 is possible but it moves you out of streetablilty pretty fast.
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I guess I need to ask why 425 HP isn't streetable. I know of several cars around me that produce more than that and are driven all the time.
 
curious too?^^ well it doesnt have to be exactly 425, just thought it would be nice to have a bit more umph for the car. i guess i didnt take into concideration body twist and no top support. i guess i should think my 375 or so?
 
425 hp is not the issue. Getting a stock bore, non stroked 340 to that power level through stock intake, exhaust manifolds and AVS carb is where the problems come from.
 
Little offtopic. How much hp would be possible from a non stroked 340 with stock bore or 0.30, 10:1, edel heads, rpm intake and TTI headers? Sorry for ot...
 
Depends on which heads (cc wise 63 or 65), how much porting, the cam and piston/compression ratio.
That being said, my engine guy said I'd be making ~400 to the setup your talking about Dusterfreak
 
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