355 gears. Or more ?

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A Body 440 WHY NOT said:
Thanks for the info !
The isky cam has 530 lift and 248 degrees of duration at 050". Total duration is at 296.
Looks like I went " more is more " with the cam !
Should be a stout set up.
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That's not a big cam in a 440 by any means but if it's cut on a narrow LSA it will certainly act and sound like it is.

What is the LSA on your cam?
 
So 248@.050, .530, 108LSA.

It's going to go bump but it could be much worse.
 
roccodart440 said:
Lets break this down a bit.

first off, 3.55 gears in a big block dart will be ok for strip use, fine for spirited street driving and highway friendly.

I don't know what a fat isky cam is, I'm assuming you have some lopey *** idle. Unless you can provide the cam specs that doesn't really help.

I can guarantee you with absolute certainty that your 2600 stall converter isn't enough for the combo and will be the detriment to your driving experience. I'd go as far as to bet it's an off the shelf piece that if you are lucky might perform like an inefficient stock converter.

As far as tires, you can get any height and width you want in 15". Go to summit racing and just keep narrowing the search criteria down. I.e. tires -- 15" wheel dia -- height ---- section width, etc. Once you find your tire, you can buy it from there or shop around.

A 235 tire height (in a 15") will be dependent on the 2nd number, i.e. 235/50R15.

Use an RPM calculator such as the one at RMS suspension to figure the tire height you require for your desired cruise speed. I base everything off 60MPH RPM because the highway is where you can quickly become most unhappy with a car. I.e. I run a 28" or 29" tall tire with my 4.56 gears to achieve 2500rpm @ 60mph. This may or may not work out at the strip but street performance and function should always outweigh strip function in a street/strip car because that's where it will live most of the time.


Last a 235 radial is useless on that setup. Get a real tire under it. My advice would be a 26x10.50 sportsman pro which with a offset shackle fits with ease and will hook it up. If you are dead set on radials go with a drag radial on the widest wheel you can fit. radials require the widest wheel per tire section width to function properly.
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How do you get the rpms that low with a 4.56 gear at 60mph
That’s about the rpm I run with a 3.23?
 
Have a friend that had a 327 Vega with an M-W 4.88 12 bolt and cherry bomb 3-1/2 inch turndowns. Great fun just going through town in that one!
 
68dodge said:
I run 4:10s in the rear with 28 x 13.50 tire, at 60 MPH, RPM is around 3400.
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Like you my Dart was always spun up pretty good, as I ran 4.56 on the street and strip with a 28.4 tire and it was far from pleasant at 60 mph, became kind of hypnotic after awhile.
Wife’s Challenger ran high 11s with a 3.91 short shifting at 5,000 and letting up a bit in high gear.
I had it leaned out when I drove to the Nats, forgot to change the springs.
 
I have 3.55s in my 440 Duster. I like it. 295/50s in the back and she turns right around 3k at 60. It’s actually cruises better with the 28x12.5 racemasters on it but I’ve never had it on the highway with those. I don’t think you are going to have any issues with dead spots with 3.55s.
 
You must have an automatic then? I have 3.91's with 295/50 too, A833, and the calculator and tach agree at 3050 rpm for 60 mph.
 
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