Hi Guys, I have 69 SS396 375 HP 4SP 410POSI, Since I live in SI and go to a lot shows in NJ, I do a lot of highway driveing, with 410 gears at 60 mph, motor is really reving.Read article about putting taller tires will make rear act like a numerically lower rear. 410 with 14 inche tires (26" tall) change to 15" tires (28"tall)act like 370 gears.Was wondering if this is better way to go then changeing gears. Thanks Bill

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BILL

"Better" is soooo subjective. Let's say it works. Faced with the same dilemna, my considerations were:
1. Change transmission to OD unit. No, too much originality lost.
2. Change wheels from 14" to 15", possible & advantage of better overall tire selection and easily reversible. No, still want to retain original appearance.
3. Change rear-end gear ratio. Yes, for me was the least detectable AND I happened to have the desired rear end laying around.

Yes, Changing to a taller tire will lower the RPM some, Wheel Dia Has nothing to do with it. You can run down the high way with the taller tires and when you get to where you are going change back.
Harley
Opinion: 4:10 are a little steep for a street Big Block that isn't raced alot.

taller tires are a cheap way to do this.it works.you probably have taller tires laying around ,this would make it free.harleys right4.10S are a little steep for street ,I have 4.88s on the street,highway speed?IT SUCKS!just my view,67rat member #199

[This message has been edited by 67RAT (edited 07-27-99).]

Harley,
To further explain the effect of wheel diameter on changing the rpm vs speed quotient:
If you are running a 7"x14" rim, your choices of a tall (>28") AND wide (>295) tire are non-existant. In this and my situation, to get the needed tire height requires 15" rims.

[This message has been edited by Alan F (edited 07-27-99).]

Bill,, Ive had quite a few BB cars with 410 gears,, and they are a bit of a pain to do any distance in,, matter of fact I just switcged the L89 car to 373s @ 50 MPR w/ the 410s I was about 3100 the 373s dropped it to about 2500,, I think the taller tires will help a little or in addition to the gear change,, in your case wantin to run in the 60 range I would go to a 355 Good Luck L89SEDAN

im having the same problem my little tired 307 has been beefed up and i don't know what ratio i have in the rear (stamp on rear says"54321" not CA etc.) and i drive highway everyday. i will have a set of welds 15" by next week and larger 235 60 tires on them which will help lower the overall rpm's from my 14" small tires and it's cheaper to find 15" tires jk