How much ET will i pickup with following changes

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B3422w5

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swapping out 727 with tight 4500 flash 8 inch convertor
Swapping in 904 with looser 5200 ish flash 8 inch convertor

Combo is 360
Airgap
950
28 tire
4.10 gear
Moderately ported eddies
1 5/8 Dougs headers
Cam is 260/264 558/558 on a 106 installed 102
Compression is 10.4
Previous best in very good air 11.26 been right around 118-119 mph

Am i crazy to think in the same air i could see 3 tenths. Just guessing the new convertor will be way closer with this big cam and show quite an improvement, then the gain going to the 904.
Car was soft out of the gate. Best ever 60 was 1.58, and on that 11.26 pass.... otherwise 1.61-1.63
Car weighs 3250-3275, will run it onto scale at track after a pass, hopefully tomorrow night if i get a couple of minor things finished up.

Thoughts?
 
I would say the 904 trans should pick you up .15 .....and the converter should help the 60 ft time which do look soft...I was going to mention the 4.10 gearing but I see only 28 inch tall tires so that is not so bad...
With the 4.10 I might have considered the low gear set for the 904 but it is what it is....

So I think 3 tenth is pretty doable ....have fun
 
70aarcuda said:
I would say the 904 trans should pick you up .15 .....and the converter should help the 60 ft time which do look soft...I was going to mention the 4.10 gearing but I see only 28 inch tall tires so that is not so bad...
With the 4.10 I might have considered the low gear set for the 904 but it is what it is....

So I think 3 tenth is pretty doable ....have fun
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I agree. The converter is a big deal.
 
yellow rose said:
I agree. The converter is a big deal.
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Kinda what i was thinking. Gonna guess peak torque is well past 5k rpm. And with that tight 4500 and large cam figured that would knock some bottom out of it. Making it a softie out of the gate like it was
Hoping this new convertor makes the car “ like” that camshaft more.
 
70aarcuda said:
I would say the 904 trans should pick you up .15 .....and the converter should help the 60 ft time which do look soft...I was going to mention the 4.10 gearing but I see only 28 inch tall tires so that is not so bad...
With the 4.10 I might have considered the low gear set for the 904 but it is what it is....

So I think 3 tenth is pretty doable ....have fun
Click to expand...

Bought the trans used on here from a member. Its a Cope built unit with A&A brake, billet drum, yada, yada. Dont know if its low gear or not, it could be.
Will find out tomorrow night on the 1/2 shift going down the track.
I just footbrake with the rearend thats in the car, even though its a brake valve body
 
Good luck, on a soft launch, what's tires ,and chassis set up ,in perspective?...
 
Abodybomber said:
Good luck, on a soft launch, what's tires ,and chassis set up ,in perspective?...
Click to expand...

275 hoosier DOT radial, ladder bar with single adjustables, stock front end with singles..... 69 Dart
I leave at 2K off the foot, shift at 6, was trapping about 6200/6250 . Car was deadly consistent in the 60 foot from outing to outing, just fairly doggy
Might bump it up couple three hundred revs. Bone stock 360 bottom, so havent really tryed to lean on it.
 
Don I'd say .3 is pretty close, the converter is going to help a bunch. My old pump gas 340 ran 11.60 with 1.54 60's with a 4.30 gear and a 275 radial. The 4.30's after 3.91's picked it up less than .01 in 60' and not much more in the 1/8.

I'll be watching as I still haven't ruled out a 904 for my Dart.
 
B3422w5 said:
275 hoosier DOT radial, ladder bar with single adjustables, stock front end with singles..... 69 Dart
I leave at 2K off the foot, shift at 6, was trapping about 6200/6250 . Car was deadly consistent in the 60 foot from outing to outing, just fairly doggy
Might bump it up couple three hundred revs. Bone stock 360 bottom, so havent really tryed to lean on it.
Click to expand...
That's honest goodness...Like the tire choice....
Best of luck, man.
 
We run the 904 low 1st gear it will help get it moving the 904 is lighter anyways you will probably pick up some rpm as the drop back on the shifts will not be as far,we went from our 9.5 to our 8 inch with our 360 and it gained apprx 300 rpm through trap so yea .3 in the qtr i can see that,have fun that 1-2 shift will come quick me and my rev limiter will attest to that:usflag:
 
Just drove it for the first time since the swap. Vert is definately looser than what i had. Didnt flash it, will play with it at the track hopefully tomorrow night. Be the first time out this year. Wanted to wait and get this done before taking it out.
 
That converter will help out a lot with that cam, more rear gear or low gear set would be prolly better, that cam has some long duration.
 
I think you will probably see close to 0.3, but most of that will be due to the trans swap (and some due to the converter). I think you would see a bigger gain if you replace the Air-gap with a Victor.

On my old 410 with a smaller cam (248/254) I picked up ~ 2 tenths swapping from the Air-gap to the Victor. With your combo I think it would definitely like it.
 
I think given the differences in 727 and 904, plus the convertor, assuming it hooks, you'll get more than .3. Not a ton more, but more. Stick a set of 4.30s in it and it will pick up more. Heavy car for 4.10s and a stock stroke...
 
flyfish said:
I think you will probably see close to 0.3, but most of that will be due to the trans swap (and some due to the converter). I think you would see a bigger gain if you replace the Air-gap with a Victor.

On my old 410 with a smaller cam (248/254) I picked up ~ 2 tenths swapping from the Air-gap to the Victor. With your combo I think it would definitely like it.
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I had a single plane mopar intake on it, and it ran better with the airgap on it. Just figured only running it 6k like i do the motor liked the dual plane better.
That said, i plan on buying a victor for the 418 motor i have in the works. Remember, the motor in the car now isnt a stroker, just a 360
I may put a victor on this 360 just to see what it does before i retire it though, worth trying.
 
moper said:
I think given the differences in 727 and 904, plus the convertor, assuming it hooks, you'll get more than .3. Not a ton more, but more. Stick a set of 4.30s in it and it will pick up more. Heavy car for 4.10s and a stock stroke...
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Agree. I drive this car on the street a lot, so at some point i have to compromise a bit for driveability.... lol
But yea, would love to try a 4.30 gearset. Will see what it does with the trans/ vert swap and go from there.
 
My experience with swapping out a 3.91 for a 4.30 wasn't worth the work or the money. Your mileage may vary though.

Don are you going tonight?
 
justinp61 said:
My experience with swapping out a 3.91 for a 4.30 wasn't worth the work or the money. Your mileage may vary though.

Don are you going tonight?
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Yep. Might rain later in the evening around 9 or 10 but should be in the lanes by 7, likely get 3 or 4 hits.
Just pecking away here at work getting truck/ trailer/ car around and saddled up. Have a bad hip i am getting replaced soon, and no help today so just get stuff around a little at a time.... lol
Not good air today, nothing like it ran that 11.26 in last fall, but i should get a pretty good idea how much stouter it will end up being, by comparing it to similar air last year when it typically ran low to mid 40’s.
 
B3422w5 said:
I had a single plane mopar intake on it, and it ran better with the airgap on it. Just figured only running it 6k like i do the motor liked the dual plane better.
That said, i plan on buying a victor for the 418 motor i have in the works. Remember, the motor in the car now isnt a stroker, just a 360
I may put a victor on this 360 just to see what it does before i retire it though, worth trying.
Click to expand...


You may want to reconsider the single plane. The converter will do wonders to get through the weak spot in the middle.
 
802DBB59-3186-4156-9C81-222621AF273A.jpeg
Saddled up
 
Weather not looking good here in SW Michigan. Looks like rain marching up from the South will be here in under an hour, and stay a good while. Way sooner than they said.
Gonna give it another 1/2 hour and then undo everything and get if off the trailer while i still can.
Sucks. Really looking forward to getting her out tonight
 
B3422w5 said:
Weather not looking good here in SW Michigan. Looks like rain marching up from the South will be here in under an hour, and stay a good while. Way sooner than they said.
Gonna give it another 1/2 hour and then undo everything and get if off the trailer while i still can.
Sucks. Really looking forward to getting her out tonight
Click to expand...


We have a saying where I grew up. Mother Nature is a mother bear.
 
The car looks great Don.

It's raining here too, I was going to Bowling Green to the NMCA/NSS race tomorrow but there is a 80% chance of rain there. Hate to drive an hour and half to get rained on and not see any racing.
 
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