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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: str8bloc on December 22, 2010, 11:17:51 pm

Title: changing gears
Post by: str8bloc on December 22, 2010, 11:17:51 pm
i have 3.08s right now thinking 3.73 or 4.11 what do u think itll be street/strip with a th350 and a 383
Title: Re: changing gears
Post by: acefoxx on December 22, 2010, 11:30:29 pm
I have 3.73 in mine with a th350. My rear end is a 14 bolt with posi out of a 91 454SS. I couldn't imagine trying to drive it on the street with any shorter of a gear like 4.11s or what not. I got real good 60 ft times with them. Here are my best time slips.
Title: Re: changing gears
Post by: ohio hab on December 23, 2010, 11:30:32 am
I have 3.73's in my rear axle assembly. You can also run with the 4.11's depending on what size your tire height is, with good results and decent street driveability.
Title: Re: changing gears
Post by: Captkaos on December 23, 2010, 12:05:03 pm
3.73 with a TH350 and a 2WD truck with less than 30" tires it going to be on the ragged edge of sanity.  I found 3.42's are the best ratio in that situation.
Title: Re: changing gears
Post by: Stewart G Griffin on December 23, 2010, 01:23:35 pm
Too many unknowns to tell.  i would test with the 3.08's, if there's wheelspin work on solving that first.
Title: Re: changing gears
Post by: bobcooter on December 23, 2010, 02:30:59 pm
4.11's will be way more "strip" than "street".
Title: Re: changing gears
Post by: str8bloc on December 23, 2010, 09:14:01 pm
well the most straight line i drive is like 2 miles. the 308s are way to sluggish for me i want more umph. the street tires im using are 235 75 15 and the dots are 325 50 15
Title: Re: changing gears
Post by: str8bloc on December 23, 2010, 10:59:02 pm
was it a straight bolt in for the ss rear end?
Title: Re: changing gears
Post by: acefoxx on December 23, 2010, 11:39:12 pm
Nah, I just cut the pearches off and set the angel and welded on the new ones. The width was perfect though. I later switched to a coil over 4 link.
Title: Re: changing gears
Post by: lechez71 on December 27, 2010, 09:55:49 pm
since you dont do lots of driving on the highway, i say 4.11 but if you plan on driving it go 3.73. with the 4.11 and a 28" tire at 65mph your rpms would be around 3,300 that would suck for highway use. if it still slow off the line you need more HP. ;D what stall verter do you have?
Title: Re: changing gears
Post by: 1980c10 on December 28, 2010, 11:02:23 pm
I had 4.11 with a 30.5" tall tire, but I had overdrive and couldn't imagine driving it much without the extra gear. You could consider an overdrive trans if you're are feeling pretty serious about the 4.11.
Title: Re: changing gears
Post by: str8bloc on December 29, 2010, 08:47:52 pm
how was it on the overdrive. monster transmission is about 1000 for the setup, but i wanna drop the tranny and the gears now. then build my stroker. overall i want a 450 hp 388,700r4 and 4.11 gears.with this setup i think itll be a bad street machine.
Title: Re: changing gears
Post by: lechez71 on December 29, 2010, 09:15:13 pm
if you plan on the 700r4 go with 4.11. thats what im getting. i have a 4L60e tranny. youll have the extra gear so it wont be bad. i figured with 28" tire, 4.11s and the gearing of the 60e tranny at 65mph ill be spinning about 2200rpm.
Title: Re: changing gears
Post by: 1980c10 on December 29, 2010, 10:25:05 pm
if you plan on the 700r4 go with 4.11. thats what im getting. i have a 4L60e tranny. youll have the extra gear so it wont be bad. i figured with 28" tire, 4.11s and the gearing of the 60e tranny at 65mph ill be spinning about 2200rpm.

That sounds real close to what I had with the 4.11s and a 5 speed.

So why not build your engine and trans, drive it, see if it feels like you need a lot more?
That's my approach with my current project.
Title: Re: changing gears
Post by: str8bloc on December 30, 2010, 04:29:22 pm
either way i think ima use my 3 speed with 4.11s for now