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????
1999 GMC Sierra SLE sc sb 4.8l 4L60E, Comp 1.75 roller rockers, graniaelli maf, garneaelli wires, Aem brute force intake, BBK 80mm tb, Nelson tune, 2/4 drop, Denali rims, custom grill, Denalli guages, Edelbrock IAS shocks, Tahoe E-fans, Nelson harness, and tune, McGaughy's 2" drop spindles, New matched coil springs, Air Lift rear lowerd air bag kit, Air Lift wireless remote
List of things to do
4.10 gears and a new posi, Lt headers, Cam, Heads, Intake,
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????
1999 GMC Sierra SLE sc sb 4.8l 4L60E, Comp 1.75 roller rockers, graniaelli maf, garneaelli wires, Aem brute force intake, BBK 80mm tb, Nelson tune, 2/4 drop, Denali rims, custom grill, Denalli guages, Edelbrock IAS shocks, Tahoe E-fans, Nelson harness, and tune, McGaughy's 2" drop spindles, New matched coil springs, Air Lift rear lowerd air bag kit, Air Lift wireless remote
List of things to do
4.10 gears and a new posi, Lt headers, Cam, Heads, Intake,
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.
1999 GMC Sierra SLE sc sb 4.8l 4L60E, Comp 1.75 roller rockers, graniaelli maf, garneaelli wires, Aem brute force intake, BBK 80mm tb, Nelson tune, 2/4 drop, Denali rims, custom grill, Denalli guages, Edelbrock IAS shocks, Tahoe E-fans, Nelson harness, and tune, McGaughy's 2" drop spindles, New matched coil springs, Air Lift rear lowerd air bag kit, Air Lift wireless remote
List of things to do
4.10 gears and a new posi, Lt headers, Cam, Heads, Intake,
Holy crap YES.
if you had 245/75R16s stock, the new ones are about .5 in shorterOriginally 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.
1969 Chevy RCLB C10 350/TH400 SOLD
2007 Chevy RCSB 4.8 4x4 LS SOLD
2008 Chevy RCSB 5.3 4x4 LT SOLD
2010 Chevy CCSB 6.2 4x4 LT SOLD
2005 GMC CCLB DRW 6.6 Duramax 4x4 191,000 and counting
2013 FORD CCSB F350 6.7 Powerstroke 4x4
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.
2014 GMC Sierra Crew Cab
-5.3
-Gibson Exhaust
i got 3.90 and they are about 2100rpm at 70....gets better gas mileage on the hwy than my 3.42
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