Ok well i just remembered i had an old 86 or so s-10 blazer out in my back yard, so i just took a trip up there and low and behold, it has a 7.5 with posi 3.73 gears. Tomorrow i plan on ripping them out and hopefully with the approval of some of you here i will put those gears in my cutlass rear end (its got 2.41 gears). Now my question is is it easier to take the transmisson out of the blazer and remove the transfer case andput on a tailshaft or should i just buy a 200r4 or 700r4 trans from the auto wreckers???
I think i got it figured out
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also what would you expect the decrease in fuel economy to be like 20% or something??? i don't have a trans with overdrive yet so just curious???
What trans does the Blazer have? If your Cutlass has an Olds engine in it, the bellhousing off the Blazer might not be right. If it has the 200 R4 it should have the right bolt pattern on it.
dan2286 said:
Can't speak for his car but most canadian G body cars had the 305 chev instead of the olds 307
If it's an 86, the trans will not work. It probably has the 2.8 V6 60 in it, which uses a different bell housing pattern than anything seen in a G body. Also, the amount of work to transform it from a V6 4x4 trans to a 2wd V8 trans would simply not be worth it. It would cost too much compared to a good used TH200 4R, which I think is the best choice because it is a bolt in.
k well what about the gears from the rear end that will work for sure correct??? Its a 10 bolt 7.5 rear in both, but the balzer has 3.73's with posi that i want to put in the rear of my cutlass that has 2.41's and no posi.
Also any idea on how much worse my gas milage would be untili got the trans with overdrive??? Like 20% worse or something??? I will prolly go by one from the wrecker. (o and it has the chevy 305 in it)
Also any idea on how much worse my gas milage would be untili got the trans with overdrive??? Like 20% worse or something??? I will prolly go by one from the wrecker. (o and it has the chevy 305 in it)
It's a tradeoff with the mileage. It will be worse on the highway, but may improve or stay roughly the same in low speed city driving due to the increased torque multiplication and decreased need for additional throttle. As for how to do it, I do not really know as I have never installed gears in an axle before. I have always just bought housings that came with the right gears. You will need to set up the pinion depth and contact pattern for the gears. As long as the spider gears in the diff have the same spline count as your axles, the diff will work in that axle with the 3 series gears you have.
Your Olds has 26 spline axels. I think depending on the year some S-10s or Blazers whichever you have had 26 spline axels and others 28. Not that it would neccessarily be a deal breaker if it has 28 spline as you can get aftermarket axels for reasonable money and it is a good upgrade if you ever wanted to make her fast. Well that with a support cover which you can check out at www.taperformance.com.
Anybody can swap a whole rear drum to drum but swaping out gears and getting something that wears right and don't wine is a bit of a crap shoot if you are not experienced with the right tools, shims, etc. You might talk to a place like Randys ring & pinion and ask them about what you should have on hand / cheat sheet for doing the install right the first time. They or someone like them should have good advice or maybe someone on here can pipe in. Also as I believe 85 Cutty is refering to above you may need an adapter or something to go from a 2 series carier (2.14 to 3.08 gear) to a 3 series carier (3.23, 3.42, 3.73+)
I am surprised your 86 does not have a 200-4r. If it does not its what I would recommend. With it your overall mileage should not change much if you do a mix of city & highway. I went from 2.56 to 3.73 with a 307 and only lost a little over 1 mpg. 3.73 x 67% (overdrive) leaves a final drive ratio of 2.49, not far from the 2.41 you have now. If you find a 200-4r out of a 442/GN/Type/MCSS, you get stronger shifts with higher shift points etc. or at least get a good shift kit from someone like www.ckperformance.com. I bought theirs on special for $99. You are looking at makeing some major upgrades to your car for reasonable money. These cars are some of the easiest cheapest & best cars to make a fast driver, street strip, semi pro tour, or drag car, out of.
Anybody can swap a whole rear drum to drum but swaping out gears and getting something that wears right and don't wine is a bit of a crap shoot if you are not experienced with the right tools, shims, etc. You might talk to a place like Randys ring & pinion and ask them about what you should have on hand / cheat sheet for doing the install right the first time. They or someone like them should have good advice or maybe someone on here can pipe in. Also as I believe 85 Cutty is refering to above you may need an adapter or something to go from a 2 series carier (2.14 to 3.08 gear) to a 3 series carier (3.23, 3.42, 3.73+)
I am surprised your 86 does not have a 200-4r. If it does not its what I would recommend. With it your overall mileage should not change much if you do a mix of city & highway. I went from 2.56 to 3.73 with a 307 and only lost a little over 1 mpg. 3.73 x 67% (overdrive) leaves a final drive ratio of 2.49, not far from the 2.41 you have now. If you find a 200-4r out of a 442/GN/Type/MCSS, you get stronger shifts with higher shift points etc. or at least get a good shift kit from someone like www.ckperformance.com. I bought theirs on special for $99. You are looking at makeing some major upgrades to your car for reasonable money. These cars are some of the easiest cheapest & best cars to make a fast driver, street strip, semi pro tour, or drag car, out of.
Maybe i will just take it all to work one day and get on of the other experianced techs to do it. I have never changed a ring and pinion so maybe i should leave it to one of them. As for the trans mine has a th350 with a shift kit, so no overdrive. I guess i will phone up the auto-wrecker and see what he has.
Does anyone know for sure if i need an adapter to put the gears in????? If so where can i get one??? O and as far as axle splines go can I use the axles out of the blazer??? They are the same length are they not???
Does anyone know for sure if i need an adapter to put the gears in????? If so where can i get one??? O and as far as axle splines go can I use the axles out of the blazer??? They are the same length are they not???
Re the gas mileage....all I can say is the engine will be turning over 50% faster in high gear with no overdrive. From around 1800 at 60 mph to around 2800. (3.73/2.41)
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