What will it run

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Just under 300 horse, as according to Wallace dragstrip calculator, given the 3250# car running 13.0 @ ~105mph. Not meant to be an end all, be all. Just a tool. Your motor is probably cranking out a little more than that, just needs a little launch improvement to utilize a little better.

Not bad for a heavy dog actually.
 
My second run I ran a 13 at 103 but 60 foot 330 and 1/8 were faster than my run that I went 12.93 at 108
 
with the old combo I never successfully made it down the track
 
I did play with timing first run total was 37 second run bumped it up to 39 third run brought it down to 35
 
My 340 was 10.5:1, 260cfm 587 heads, untouched Victor intake, 1-3/4” headers, and a 263/267-108 SFT cam.
8” converter that flashed 4900, 5.13 gears, 30” slicks.
Best ET’s were shifting at 7500. Only went 7k thru the traps.

At 3550lbs (68 B body) the best it went was 11.60’s@116.
Mid-1.60’s in 60’

After the motor was pulled it ended up on the dyno.
Made 400tq/454hp.
After that it got the manifold tweaked and the heads milled to get it to 11:1.
Back on the dyno........ it was like 412tq/478hp........ then got sold.

I’m wondering if the OP’s 60’ times are from the component mismatch, or a traction issue, or both?
 
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PRH said:
My 340 was 10.5:1, 260cfm 587 heads, untouched Victor intake, 1-3/4” headers, and a 263/267-108 SFT cam.
8” converter that flashed 4900, 5.13 gears, 30” slicks.
Best ET’s were shifting at 7500. Only went 7k thru the traps.

At 3550lbs (68 B body) the best it went was 11.60’s@116.
Mid-1.60’s in 60’

After the motor was pulled it ended up on the dyno.
Made 400tq/454hp.
After that it got the manifold tweaked and the heads milled to get it to 11:1.
Back on the dyno........ it was like 412tq/478hp........ then got sold.

I’m wondering if the OP’s 60’ times are from the component mismatch, of a traction issue, or both?
Click to expand...


I think we know the issue and told him earlier. Wrong cam or wrong converter. Those two won’t dance well together. I Dont think he ever gave the first converter a chance.
 
So you think I would’ve been better off keeping the converter at 4500 with this camshaft
The car just felt like a slug on the street like it was always reving and not moving not
moving this engine combo is kind of hodgepodge unfortunately I bought it years ago and did not build it you don’t think it could get down to 12.5
 
F21 said:
So you think I would’ve been better off keeping the converter at 4500 with this camshaft
The car just felt like a slug on the street like it was always reving and not moving not
moving this engine combo is kind of hodgepodge unfortunately I bought it years ago and did not build it you don’t think it could get down to 12.5
Click to expand...
You need a 5500 or more, that cam is huge.
Matter of fact a good tuner might run pump gas at 13.0:1 cr with that cam.
 
F21 said:
So you think I would’ve been better off keeping the converter at 4500 with this camshaft
The car just felt like a slug on the street like it was always reving and not moving not
moving this engine combo is kind of hodgepodge unfortunately I bought it years ago and did not build it you don’t think it could get down to 12.5
Click to expand...


That particular converter may have been wrong for you but not the stall. I haven’t played the street game for to many years so I’m not the guy to ask. But many many of my friends are running higher stall than 4500 on the street and not having that issue. Just make sure you monitor trans temp and have proper cooling.
 
The 4900 stall speed I was seeing with my 8” converter behind the 340 wasn’t really enough.

Behind a 383 with a 256/262 cam, in the same car but with 4.56’s that 8” converter would flash about 5400.

That combo worked pretty well, with 60’ times in the mid/low-1.50’s(1.51 best).

“if it were me”, I’d replace the 272/280 cam with something quite a bit shorter, then revisit that converter afterwards.
 
Oh **** maybe I am wrong about the duration at 50 here’s the specs

1C6DB61D-BCF2-4838-A306-671005517BA7.png
 
Yeh..... way different.
Good street/strip type cam.

See if you can get someone to video the back tires at the launch next time you go.
Unless it’s spinning, the 60’ times are way off from what should be possible.
 
F21 said:
Oh **** maybe I am wrong about the duration at 50 here’s the specs

View attachment 1716107097
Click to expand...
I run that cam in my dart 3250lbs 340/A999 dana 4.10 26" nitto drag radial 10" TA converter flashes to 3400 of the line. Car will run 11.80s at 2000' DA in summer air and 11.60s in good winter air. 34* timing, 72/86 9.5 power valve .064 PVCRs in a Demon 750DP blue cams #1 hole 36/37 nozzles works for me.
 
I’d like to hear a little about the OP’s 750 carb.
The jetting sounds huge for a typical Holley 750 on a 400-425hp 340.

My dyno mule 750/4779, that I use on a lot of stuff in the 400-500hp range, has 72pv/80 Jets in it and on a 420hp 360 the A/F ratios were in the high-12/mid-13 range.

Looking at the overall combo some more, and it probably wouldn’t make any difference........ but I’m not luvin the orange box ignition.
 
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The carb has 82s in the front 86 in the rear 3.5 power valve in the front blocked off in the rear I had 79s in the front and 82s in the rear and it seem to stumble when I smash the throttle maybe I should play with jetting some more She is on the rich side

I went with the orange box after my MSD 6 AL kept cutting out when it was hot
 
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