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Discussion in 'The Garage' started by hi pinion, Feb 20, 2005.
Any one running 538 gears in there blazer? If so , how are they? Are they streetable?
Not with 35's in my opinion. 5.13's are plenty low and 5.38's would seem like it would kill top end and definantly fuel mileage. But....I have never had either ratio.
2500 @ 70 really isnt that bad.
I was kind of looking for someone with some real world , hands on kind of experiance,someone who is running these.
If someone had the need for gears like that, chances are they'd be running one ton axles...and 5.38's aren't officially out for a 14 bolt yet.
the 5.38s are already in the Sterling rear, which from what i hear is a very stout piece, offered in the rear of Ford trucks. the only thing that would cause me to shy away from the deal is the fact that its welded, and he's driving it on the street.
5.38's is what I want to end up with....Of course I think it would be fine....
What size tire? Overdrive?
For the record, there was a rumor on Pirate last fall about someone coming out with a 5.38 for the 14 bolt (Yukon maybe?). Don't know if it's true, just something I read.
I run 5.38's in my 'glas buggy. Trans has a mild OD and with 31's it's only 3k for 60 MPH.
It's not a rumor, they'll be out VERY soon.
I was going to run 5.38s in mine but I'm getting a doubler instead.
IIRC he will have 35's and does have a TH700R4.
There are a lot of Gear Calculators available to help you make that decision. I developed one that you are welcome to use, if you have Excel. It’s posted on Race-Dezert. http://www.race-dezert.com/forum/showthread.php?t=12468http://www.race-dezert.com/forum/showthread.php?t=12468
No no, run the 5.38's AND a Doubler.
How would the pinion on the 5.38 compare to that of a 5.13?
I haven't seen any posts reguarding the tooth counts for the r&p. would think they're fairly similar, probably 1 tooth less on the pinion if that.
Honestly, I don't feel that would be a good combo with a 4 speed. Low-low would be too low, low-high would not be low enough, and for mud, I'd be stuck running in high-high and being too high or low-high and being too low.
I think the 4.10s will be ideal with a doubler. It allows me to keep the ratios I have now, and have the super low of the doubler for the hard stuff.
I have resisted re-gearing because I wasn't sure if I would want a doubler, and because of my 10 spline 465 I didn't have a whole lot of options. I have been talking to Northwest Fab about this idea since even before his doublers were released, and I feel that for the $$ expended, the doubler is my best option.
If I ever had R&P failure or whatever, I can fix it with nice used stock parts, too, another plus.
seems like a k5 won't be able to get to 240 mph at 6000 rpm.
At first that seems right with the whole 5.38 gears and 35's being at 2500 for 70 mph but since the chart goes on to tell you that with 3.73 gears, a k5 hits 140 mph at 3500 , I start thinking the real world speeds would be a lot less for a lot more rpm.
Anybody have 5.13's or 4.88's with a 700R4 and 35's that they have been out on the highway with? what is the speed for rpm?
i've got a gear ratio/speed calculator that i've been using for years, i got it from Team Chevelle. its has been very accurate. of course these calculations are assuming perfect conditions, with no converter slip in OD at 65mph, and a true 35" tire. i'd give it 200-300 rpms more, and it shoudl be dead nuts.
4.10s - 1800 rpm
4.56s - 2000 rpm
4.88 - 2150 rpm
5.13 - 2250 rpm
5.38 - 2350 rpm
6.72 (rockwells) - 2950 rpm
7.17 - 3150 rpm
those rpms are for 65?
clearly stated that in the post didnt i?
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