i have an 83 cutlass brougham. it was an original v6 car but it has a 350 now. i plan on doing a lot of street beating with this car and the stock gears are way to tall! i have a 350/ th350 setup and i have 225 60 r15 tires on the rear. my question is what would be the best gear ratio to get with this set up. i dont need to go any faster then around 100 or so, but i want to be able to have a nice launch to. the car is more then likely going to be going more directions then trait most the time so strength isnt a huge issue since i wont be going to the track alot. i would like to swap a limited slip or locker in the car also. i have heard that if i get a camaro gear set up it will bolt in but i need difforent axle shafts. what axle shafts, differential, locker/ limited slip should i get? any help would be really appreciated. i cant afford to swap a 9 inch in right now so anything to get me by for awhile would be great if it will do what i want it to for awhile. thanks
stock differential options on an 83 cutlass. any suggestions
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u might be nice with a 7.5 limited slip with a 342 gear, thats what i had in 1 of my old cutlass and it had a truck 305 and it got sideways and had a super nice take off with that rear end.
yeah i'm not sure what gear ratio to go with. my dads sayin i should go with 4.11 or 3.56's or something similar but i'm just not sure. what kind of locker/ limited slip would be best or atleast decent for a year or two85salonn442 said:
I have a 305/TH350 with 3:73s and I love it.But then again, I also have 24" tall tires. Revs at about 2k going 35mph.
Alright any posi from a gbody 81-88 will install in to your rear. Monte carlo ss's had them and they were an option on many if not all cars. Mae sure its functioning correctly. i actually got mine on ebay for $125. You don't need to buy new axles for this so it is very convenient. You will need to make sure that it is a 26 spline unit if you do not want to buy new axles however. If it is a 7.5" from a gbody, it will definitely be for 26 spline axles.
Differentials can either be a series 2(3.08 and down ratios) or a series 3(3.23-4.56 ratios). Depending on which series carrier you go with compared to the one you have, you may need to buy a ring gear spacer. If your car is currently equipped with a #.08 and lower, it is a series 2 carrier. If you plan on upgrading the carrier to a series 3, you will need to buy a ring gear spacer in order for the series carrier to properly fit in your housing.
If you decide to keep your series 2 open differential, you can still run 3.23-up gears as long as you run a ring gear spacer or buy aftermarket thick gears.
I personally would recommend 3.73 gears for performance or 3.42s for a little of both performance and economy. Definitely do not go with 4.11's. They are not very streatable gears and I think you would regret using them. On a side note: I do not believe GM 3.56 gears exist lol.
If you have anymore questions or clarification feel free to ask.
Differentials can either be a series 2(3.08 and down ratios) or a series 3(3.23-4.56 ratios). Depending on which series carrier you go with compared to the one you have, you may need to buy a ring gear spacer. If your car is currently equipped with a #.08 and lower, it is a series 2 carrier. If you plan on upgrading the carrier to a series 3, you will need to buy a ring gear spacer in order for the series carrier to properly fit in your housing.
If you decide to keep your series 2 open differential, you can still run 3.23-up gears as long as you run a ring gear spacer or buy aftermarket thick gears.
I personally would recommend 3.73 gears for performance or 3.42s for a little of both performance and economy. Definitely do not go with 4.11's. They are not very streatable gears and I think you would regret using them. On a side note: I do not believe GM 3.56 gears exist lol.
If you have anymore questions or clarification feel free to ask.
see but if you were 2 go with a 4.11 gear and there isnt that much work done 2 your 350 its goin 2 take away from the power because the gear is to big.
I would get more tire under it first, 275/60 15 would be good.
Based on your combo (th350,225/60) and goals, I say gear it. Plus gears cover up SBC lack of torque.Used a 6000 rpm shift point.
==================3.73=====4.11======4.56
55mph 2nd gear 4000 rpm 4500 rpm 5000 rpm
55mph 3rd gear 2700 rpm 3000 rpm 3300 rpm
65mph 2nd gear **************************6000 rpm
65mph 3rd gear **************************4000 rpm
75mph 2nd gear ***************6000 rpm
75mph 3rd gear ***************4000 rpm
80mph 2nd gear 6000 rpm
80mph 3rd gear 3900 rpm
100mph 3rd 5000rpm*** 5400rpm*** 6000mph
These don't account for torque convertor slippage. Your actual rpm will be higher by whatever slippage your convertor has.
Based on your combo (th350,225/60) and goals, I say gear it. Plus gears cover up SBC lack of torque.Used a 6000 rpm shift point.
==================3.73=====4.11======4.56
55mph 2nd gear 4000 rpm 4500 rpm 5000 rpm
55mph 3rd gear 2700 rpm 3000 rpm 3300 rpm
65mph 2nd gear **************************6000 rpm
65mph 3rd gear **************************4000 rpm
75mph 2nd gear ***************6000 rpm
75mph 3rd gear ***************4000 rpm
80mph 2nd gear 6000 rpm
80mph 3rd gear 3900 rpm
100mph 3rd 5000rpm*** 5400rpm*** 6000mph
These don't account for torque convertor slippage. Your actual rpm will be higher by whatever slippage your convertor has.
thanks for the feed back. yeah i know my dad was saying something about 4.11 and 4.56 gears and threw some other gear ratio out there i just wasnt for sure what he said. him and his buddy's used to run older chevelle's and camaro's with these gears i guess. but they all had 4spd manuals. judging from all the suggestions 3.73 might be about right for me with maybe a stock limited slip. i do plan on putting new tires on it soon. the tires on it are junky and need to be replaced but i figured i would burn them up first. any ideas where i can find a stock limited slip and all the necessary parts to swap my gears. i believe my car has the series 2 carrier since the gears in it are so damn tall. i would tell you the rpm/ speed in each gear but the speedometer is broken. i hate to be completely ignorant but i dont really know a whole lot about the stock rear ends in these cars. are new limited slips available for these? i really appreciate all the help so far thanks guys
85salonn442 said:
I have to disagree with you on that. My car has 3.73s with a 24" tire. Probably the same as 4.11s with normal size tires. And I'm running a totally stock 305. And no loss of power. At least it doesn't seem like it, considering the new HEMI trucks, new Mustangs, and older cobra, a Skyline, and many other cars lose light to light against my car.
The only downside is revving at 3000RPM+ at highway speeds. But I'm building it for the street, not the highway. SO that's ok lol.
just baught a limited slip out of a newer 6spd Z28 camaro with 3.48 gears for $100. have to get some 28 spline axles but a few more splines then stock cant hurt. any thaughts on 3.48's with my tire size and engine/transmission setup? its prolly going to take a few weeks to get it but thats fine. i wont be able to drive the car for awhile now any way. forecast says 2-5 inches of snow tonight.... i'm not to impressed at all
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