6 sec street Duster combo?

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HP2

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Dear Mopar gent's,
Here in Sweden we have our own "Drag Week" event and I just bought a 71 Duster for next years event.
You get punished for nos, turbos, wide slicks etc and I will try to keep it "simple" with an normally aspirated LA and 295's street slicks to compete in the 'True Street Class'. With wider tires you will be moved up to faster classes. All tracks are 1/8 mile.

I don't yet know much about the Duster I have conquered but I can't stop thinking and planning. It will take some time to sell some other Mopars before I can start tearing it apart to see exactly what I have but until then I want to plan and dream a little :)

Nice and rust free body, decent/good paint, has had the leafs moved in but someone put them back to original location, fiberglass bumpers and hood, original interior and dash, Quicksilver shifter, all electrical works, expensive extra gauges, roll control, engine bay in good order, beaten up Hooker comp headers, half 2.5" exhaust with Flowmater 40's, steel braided fuel lines and an expensive fuel regulator, tank sump and Holley blue fuel pump and filter back at rear bumper, 8 3/4" and big bolt pattern all around. '73 disc brakes up front. It looks overall pretty serious and well built.

It has a 340 with Edelbrock heads and the people I bought it from said it ran 13,2. They told me they don't know s**t about tuning and it's easy to figure out. They claimed the engine was built by a serious engine builder but they had lost all the documentation. No idea of cam, CR or anything...
I have just started it and driven it around the block. It sounds healthy but slow. They have put on a new stock MP distributor (lazy adv curve) with a MSD 6AL box and the brand new Quick Fuel had the float level adjusted as high as possible so I'm not really surprised it didn't perform better. It has manual valve body tranny (forgot to check if it's a 727 or 904 but I'm pretty sure it's a 904) and stalled around 3,200 on 3rd with braking it hard.

Either the 340 is a good start or it's not, I won't know 'til I open it up but I actually think it can be.
Let's start from the other end instead.

I'm thinking of bringing only tools and an 4.56 spool chunk (that I already have) to change before and after race. I have a good 3.23 LS that would be good for transportation between the races. I also have a 518 46RH but I don't know if I will get the time for installing that for next year.

Would it be crazy to believe I could build a normally aspirated AND reliable 340 that runs consistent high 6 second runs in that Duster on pump gas? 6.9's would put me in top 10 in the 'True Street Class' among all the Chevy's.

How would your recipe look?

I will need to weld in a 6 point cage but apart from that I will try to keep it as original looking as possible.
CalTracs and monoleafs with good shocks is already on the list.
 
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First thing you need to do is run the car and find out where your at.

Start by tuning the carb. The floats should NOT be set as high as they can go.
 
You'll need around 525hp at the flywheel for 3300 lbs.
That's excellent info, thanks!
Question is how to get there in easiest and cheapest way? If it gets too costly I can use the 6.1 Hemi I have sitting, haven't decided what to do with it yet. Also have an A518 46RH I could use but if I start with that swap I'm afraid money and first of all time will set me back.
Would be more fun (and faster) to build on a 340!
 
First thing you need to do is run the car and find out where your at.

Start by tuning the carb. The floats should NOT be set as high as they can go.

Of course not, that's why i commented it like I did. Anyway, I'm sure a good carb tuning and a good timing curve won't take me into 6's. I guess it will take more.
 
To get 525fwhp@3300 to run 6.8's in 1/8th from your 340 those Eddies if stock won't do it@around 247cfm max flow, they are only around 30cfm better than stock iron heads. You'll need around 300cfm in ported form and either a solid roller or a good solid ft cam and at least 11:1CR + a tight 4500>5000 flash verter, with a 29" tyre and 4.56's you'll be turning around 6900rpm@the stripe with slip.
 
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520fwhp@3300lbs>
60 Foot E.T. : 1.50
1/8 Mile E.T. : 6.80
1/8 Mile Trap Speed : 99.89
1/4 Mile E.T. : 10.78
1/4 Mile Trap Speed : 124
 
like has been said above, take to the track and shake it down. Now you have a base to tune from. tune it the best you can and then decide how much $$$$ you what to threw at it to make your goal.
 
like has been said above, take to the track and shake it down. Now you have a base to tune from. tune it the best you can and then decide how much $$$$ you what to threw at it to make your goal.
Wish it was that easy. Remember I am i Sweden. Car needs to be on a trailer since it's not registered and inspected yet due to slow handling by the authorities, and my driving license doesn't allow me to haul heavy loads. Only one race remaining before winter and that's 8-9 hours away without trailer. No chance to test and tune on a real track with track bite before spring 2020.
 
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