I know it's been asked before but what is the modern tire size equilavent of the original 13" tires for a 1965 valiant. I'm going to 14" x 7" rims and want a little more tire so I need to know what diameter I am aiming for. If it matters the rims are lbp ralley's off a 73 e body.

6.50 13 tires are equivalent diameter wise to a 185/80 13 tire

(the older designations were 90 aspect ratio, so a 6.50 13 is a 165 / 90 13)

For 14's you can use a 195/70 14 (which I have on a 14 x5.5) or a 205/70 14 (which would work better on a 14x7 rim...........)

You're shooting for around 25" diameter, so some other possibilites are

215/65 R 14
235/60 R 14

Not sure if the 235/60 would fit................ You can use the slight differences in diameter (or pick a tire from a different manufacturer) to correct the speedo to................

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

205/70/14 are too tall- they will make your speedo read incorrect-- I think you would need to stay with the height of the 195/70/14's around 24".

or just adjust your speed according to your new tire .. when my speedo reads 60 I am going approx 66 mph-- 62 valiant 205/70/14 tires on 6" slots.

Good luck

24" is way to small........

A 195/70 14 is 24.75" diameter 205/70 14 is 25.3"

6.50 13 was about 24.6" diameter

I went from the 6.50 13's (which had the speedo reading high) to the 195/70 14s in which the speedo still reads slightly high. I'd need a 25" diameter tire to get the odometer correct (and about a 25.25" tire to get the speedo correct).

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

My 235/60/14 end up being the same diameter as my old 185/13s. I have them on 14x8 rims on my 65 Valaint with no rub,,,front or rear.

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Yeah....Im the one who destroyed this rare, vintage automobile.....

Do any of you have a rebuilt/calibrated speedo assembly? Just curious as to how accurate our 40year stuff is??

I just gauge off of the traffic flow & at 60MPH on my speedo I stay with traffic traveling in a 65MPH zone (not scientific but works)

Granted----- my traffic is not nearly as busy as most slanters- Kansas does not have a lot of people/cars compared to the coasts

Usually odometers & speedometers will be off by different amounts.

After I got the car (and before the new tires) I had the car tested at the auto club and had the following results with the really old bias-ply snow tires it had:

Odometer 3% low
Speedometer
25 indicated 25 actual
30 indicated 30 actual
40 39 2.5% low
45 43 4.4% low
50 47 6.0% low
55 52 5.5% low
60 56 6.7% low
65 60 7.7% low
70 64 8.6% low
75 68 9.3% low

average about 6.3% low (40 & above)

I then figured out what diameter of tire to get to correct the errors...

It looked like a 195/70 14 would correct the odometer and a 205/70 14 would correct the speedo. I went with the 195/70 because for some reason they were considerably cheaper and it's theorectically possibly to tweak the speedometer (adjust the distance of the magnet from the needle).

Subsequently, it looks like the odometer reads about 1% low basing the odometer reading against mapquest on a 120 mile trip...........

If I adjust the speedometer readings I should come out about here:

Speedometer
25 indicated 26 actual 4.0% high
30 indicated 31 actual 3.3% high
40 40
45 44 2.2% low
50 48 4.0% low
55 53 3.6% low
60 57 5.0% low
65 61 6.2% low
70 65 7.1% low
75 69 8.0% low

average about 6.3% low (40 & above)

Or just be lazy and say it's accurate until 40, then it's 2.5 mph high until 60, then it's 5 mph high............ so I'll go 5mph over the speed limit in town, and then 10-15 over on the highway..............

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

I started using GPS to check speedometers and set the cruise control in the assorted company vehicles I drive. On a whim, I checked my '64 Valiant speedometer. It's dead on at highway speeds (50-70 mph), as closely as I can read that needle. It's much more accurate than a certain Ford Taurus and a Chevy S10.
I don't think I'd choose tires for speedometer accuracy, but heres a site that might help:
http://www.miata.net/garage/tirecalc.html

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"When you find a big kettle of crazy, it's best not to stir it." - Pointy-haired Boss

1964 Valiant V200, 225/Pushbutton 904
BBD, CAI, HEI, LBP, AC, AM/FM/USB, EIEIO