Horsepower guesstimation?

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H2obuffalo

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Hi everybody.
I'm new to the wonderful world of classic mopar. I have been looking up stats and horsepower and was wondering how much power is under my hood on my new favorite ride. I was going to dyno her to just know for sure but wow that's pricy. So I'll list what I know about the parts I have on her and can one of you who may have the same or similar setup give me a best guess as to the power. Or is this a silly request not worth discussion.
The goods:
1972 dart swinger:
Original 318 v8 .030 overbored on recent rebuild. Less than 10000 miles.
Hooker headers
Eddy 650cfm 4barrel
Hydrolic lifters replacing tappets
Electric spark upgrade.
New dual exhaust with flowmasters.
Mild cam.
Lightweight springs in the upgraded rotor and with excellent timing adjustment and tuning
15" centerline wheels
She wont really burnout due to freeway gearing in the diff. But has terrific boost after 30 mph.
I plan on eventually replacing the tranny with a rebuilt 727 that came with the car but I need a new driveshaft rear axel and diff to make the magic happen.

Any wisdom would be appreciated.
Thanks for listening.

Here she be!

image_20170522_190434_1495560080307.jpg
 
First off, nice looking Dart! As far as horsepower you may be disappointed. I think a stock 72 318 is around 150 hp. So add depending on your cam specs another 50 hp.
 
You need to give a lot more info to get a good HP estimate. What are the cam specs? What is the compression ratio? What intake are you using? What heads are you using? Any mods to the heads?

Nice looking car though!
 
Open Diff? Wont spin the tires? It seems to me you dont have it tuned as well as might be possible. IMO, without more info, not enough timing......Initial. Just a guess. IMO.
 
Mopar Tim said:
IMO under 200 HP.
Click to expand...
Thanks for all the replies.
Im out of town but after I get back Ill try and get hold of the previous owner and verify the exact mild cam what pistons etc, and go through the service records.(my new car came with a wonderfully full file of work and parts history docs.) Do my homework and add what details I can confirm.
Thanks again for playing everyone.
.
 
Don't get too discouraged by those guesses. If it's rebuilt and you have documentation, you came to the right place to work out the tune. I bet you'll be burning tires before too long.
Find out what you have first, provide the info, and this crowd will help you get there.
 
Don't focus too much on the numbers. 318's don't usually make a ton of power but they're still great engines. I used to have one in my Dart and it while it doesn't make as much power as my 340, it could still roast tires and was fun to drive. Sounded pretty good too.

Around 200hp might be accurate but don't Fret over it (you'll always want more power). It takes away from the enjoyment of having an awesome old car.
 
Ok. I looked back through all the parts orders and maintenance/service records and confirmed the following.
Hooker headers
Edelbrock 1405 600cfm 4barrel carb
Edelbrock 7176 rpm manifold
Isky racing cam isk-160171 with new hydrolic flat tappets. Duration is listed 270/270 lift is .465/.465
Compression was tested on the rebuild at 9.0 - 9.2 to 1
Does this shed any more light to the guessing.
Thanks again for playing.
 
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Also here is a picture of my rear diff. Is it possible to change the gears on this diff to something slightly higher than freeway friendly gears i have now for a little quicker jump off the line? Or possible a suregrip swapout.
Thoughts?
Or should i find another diff.

20170704_155102.jpg
 
i agree with BlueDream.Hp numbers are very misleading.
Stock '72 - '73 340's were only 245 hp and well tuned ran very well.
 
That looks to be a 7 1/4. Not much out there for suregrips or gears! Better with 8 1/4 rear. 3.23 or 3.55 gear is better.
 
I have a 318 that's .030 over with similar spec's and my dyno (the dragstrip) says about 210hp.
First if that's a small block 727 I would sell it and use the money to buy an eight and a quarter rear end. Reason being is because any small block you put together your 904 transmission will be able to be built to handle it at much less weight. No real funs going to happen until you change those gears with that 318. I like the 355 for what you're talking about and definitely an 8 and a quarter if you just staying with the 318 for a while much more budget-minded. I do believe I had about $300 in my 8 1/4 with a 355 trac-lok. Like I did this will be easily sold one day when you decide to go crazy and start getting big huge horsepower. And at that point just skip right by the eight and three quarter and go to the Dana 60.
 
Wow, thanks for all the replies and advice.
I think I am going to keep the 904 tranny and the 318 as is. The engine runs too well for me to want to change it. I'll try and find someone to trade my rebuilt 727 for an 8 3/4 diff so i can get suregrip going and that should keep me happy for some time!
Cheers!
Heres a photo of my girl and some new kid Ha Ha!

20170609_065632_1497018685215.jpg
 
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