Ok then what is the recipe for a 425-450 horse streetable 340

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Kram1976

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I have a '67 Valiant with a 340 dated 1-21-71 and a 904 trans. dont know if stock converter or not. I dont know current c ratio but want to bolt what ever I need to get as close to 450 hp as I can. What is the cheapest way to go about this. I was going to get the heads I mentenioned in my earlier post. What do you guys think.
I want a good all around street and very occasional recreational strip rod.

P.S. I know the color sucks but for $750.00 (for the running and driving car) I did not complain. I'm thinking a matte silver like the one in Mopar Muscle. I love that car.
 

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Depends on your idea of streetable. I had a 340 that made 480hp and 450ftlbs of torque but torque peak was at 5200rpms. Ported iron heads, 11:1 compression and a [email protected]" solid flat tappet cam.
 
Build a flat top zero deck bottom end,great cam and a great set of cast iron heads,with components to match the cam and heads,and 450 will be easy,mrmopartech
 
Kram1976 said:
dont know if stock converter or not. I dont know current c ratio but want to bolt what ever I need to get as close to 450 hp as I can. What is the cheapest way to go about this.
Click to expand...

The good thing is, you have a nice light "A" body.....The bad thing is, you don't know much about what's in it.

The more info you could give the better, but at this point, i'd have to recommend a nice milder NOS kit for what you're looking to do. And i'm not a nitrous guy. :D

If you want to pull it, find out what you have, and do a complete build.....then yes, 425hp is obtainable in a fairly hot street package.
 
Stock 340 with a 150 shot.
 
how did you arrive at 450?
a stock 340 with a good converter and a gear...oh my
 
Honestly I will be happy with 400 but would love to have a light A body with a small block that puts out 450. No ryme or reason just a number that I have always wanted. To me any more than that on the street is useless. I think that would just be a great car that is a ton of fun to drive. Ive always been a GM guy but admired the Mopars. Ive had a 67 Firebird conv, 69 Z28, 86 TA, and a 2002 TA, the fastest being the stock 2002 Ta at 315 and It was fun but heavy.
With this car at around 4something ponies I think it will be a blast on the street.
Not to mention with those #s I think I can get away without having to upgrade everything else on the car eg. the trans and rear end.
 
Ok - so understanding the price differential between GM and Mopar - how much do you have to spend on it?
 
dana 60 cut to abody size 2000
hipo 727 1500
decent 440 5000
roughly $8500 (cheaper if you can get a deal on any of the above) will blast you past any of those other cars you mentioned lol.

or you could spend $4k on tricking out a 340 about half the price

or like rob said just put nos on the current engine (cheapest route)
 
I dont really have a $$ amount in mind that is why I am asking for the best bang-for-the-buck.
I have never been real keen on NOS. I want the power to be there when I step on it and not dependent on the press of a button. Not that that wouldnt be cool also but I would want that in addition to my 400-450 HP.
I think were gonna be beating a dead horse. I just need to find out how this thing is built. When I pull it to paint the engine comp. Ill pull the heads and oil pan to investigate.

Thank You guys for your input!!!!!!!!!!!!!!!!
 
...for the street think torque.
450hp in a sm blk will require a decent cam and higher rpm
which usually hurts lo rpm torque,
get advice from an experienced builder or you may have
a dud from stop light to stop light.
 
Well my 340 has 398 hp 413 tq with a basic stock 1970 rebuild ,10.5 mahle forged , pistons , mild porting on the heads with mild hyd cam . Car is a blast on the street , smoke the tires easily , starts first turn of the key . So reliable my wife can drive it . 450 hp would be easy to reach with a stronger cam and a bit more head work .
 
You can hit your goals easy with a 4" crank and the torque will come in low, not require a lot of gear or converter, and you could have a mild mannered cam too. I would not focus on HP at all for a street car, its all about torque, that is what moves the car.
 
The best bang for the buck is nitrous, hands down. If you don't want to use nitrous, then you don't want the best bang for the buck. Button dependent or not, nitrous is it.
 
How does the car run now? I would think it would beat a 02 TA just like it is. What gears does it have?
 
Put in some gears, a sure-grip, decent rear tires, and a set of headers, (cuz you're gonna need them anyway),, and see how much fun you have... then you'll have an idea how much power you need,,
 
Kram1976 said:
I dont really have a $$ amount in mind that is why I am asking for the best bang-for-the-buck.
I have never been real keen on NOS. I want the power to be there when I step on it and not dependent on the press of a button. Not that that wouldnt be cool also but I would want that in addition to my 400-450 HP.
I think were gonna be beating a dead horse. I just need to find out how this thing is built. When I pull it to paint the engine comp. Ill pull the heads and oil pan to investigate.

Thank You guys for your input!!!!!!!!!!!!!!!!
Click to expand...


That was the next question - what do you have as a "core engine" starting point?

Some very basic formulas I use to estimate costs for a factory displacement to gain some perspective:
up to 1hp/cu inch = $11 per hp.
1.05hp/cu inch = $14.5 per hp.
1.1hp/cu inch (380hp 340 or 400hp 360) = $16.25 per hp.
1.25hp/cu inch (425hp 340 or 450hp 360) = $20 per hp.

Strokers change the math a little but it's a safe bet to add 25% to any level for a non factory stroke.
 
Right now The car runs great. Im working to get it to shift correctly, rebuilding the front end and putting some money in the interior, and thinking of painting it. So as you can see I have my hands full. The paint can wait and probably will have to because I want to get it running how I want it to before that goes down. It has a 8 3/4 rear end with 3.23 sure grip so traction should be ok would be better if I get the spring re-locator. Tires are a little narrow on the rear at 225/70/14. Smokes them with out even trying. Matter of fact the car will get sideways if I let it. But seems to lack what I would like in power at any speed out of first gear. The Hurst ratcheting type shifter works well but in full auto I cant seem to get it to downshift while accelerating.
 
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