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So I have a GU6 code which is 3.42. I was going to put in a 3.73 gear set and a posi since I have a one wheel peal.... Will that make all that big of a differanc???? I drive the truck on the freeway a lot so I don't want to be to crazy... Should I go lower to like 4.10????
Gonna keep close to stock wheels or gonna go up in size? Stock converter? If you're gonna go up in tire size and you have a stock converter I'd go to lower than 3.73 (higher number).
Doesn't Ian have 3.90's? I've always thought that was a good balance and my Chevelle had both 3.73 and 4.10.
I have 17" denali wheels with 275/60/17 on her now. I don't know how much off of stock that is..... When I get the trans rebuilt I will put in a converter, I am just not sure how much stall to get. Does anyone knowe what the best posi is for a 2wd rcsb????
With a stock cam I wouldn't put more than about 2400 stall in and with those wheels and tires I would go 4.10. The gear swap isn't something you wanna do or have done more than once if possible.
Cool that gives me something to work with... Before I do a cam and all that stuff, I want to switch the 4.8 out to a 6.0. I think that will be money better spent.
Holy crap YES.
if you had 245/75R16s stock, the new ones are about .5 in shorterQuote:
Originally Posted by 99LS1
yeah, having lower gears will get you better acceleration, but if you do a lot of highway driving, that's gonna get old (and use more gas) cruising at higher rpms all the time. you're running around 1900rpm or so at 70mph, right? a 4.10 rear would put you at about 2300rpm (in 4th, of course)
just my .02
My 07 with 3.73s ran 1900 at 70, but thats with 18"s and some bigger tires.
I am running 373's with 275/55/20's and have no problems. I drive from Houston to San Antonio once a month. And I drag a trailer that weighs a 1,000 to 1,500lbs at different times. I drug the trailer with 2 street bikes weighing 1,500 we estmated all the way from Houston, Texas to Niagra Falls and then to W. Virginia and back to Texas after riding a 1,000 miles on the bikes in W. Virginia. Had no real problems. ould have used a bit more power, but the truck was pretty much stock then.
i got 3.90 and they are about 2100rpm at 70....gets better gas mileage on the hwy than my 3.42
The Detroit Truetrac is becoming the differential of choice. You can get it for a good price on ebay: GM 8.5" CHEVY 10 BOLT 8.6 DETROIT TRUETRAC POSI 913A481:eBay Motors (item 330335502533 end time Jun-14-09 09:19:01 PDT)
If you get it, make sure you run regular gear oil not synthetic. The synthetic has given a few people lock up problems.
I think the friction modifiers would be more of the issue and cause problems than it being synthetic. I've been running straight Mobile 1 sythetic gear oil in the factory weight since the gear and True Trac swap with no issues, about 5K miles.
275 is width in mm which is equal to 10.82 inQuote:
Originally Posted by 99LS1
60 is the aspect ratio which is the distance from the lip of the rim to the edge of the tire.
60% of 275 is 6.5 in
6.5x2+17(rim diameter)= 30in which is like zebra said, half inch shorter than 245/75R16