ok so i have a few questions. i have a stock 7.5 2:41 rear with 26 spline axles. a guy local to me has a 7 5/8 rear out of a 00 camaro ,2.74 rear gearing wit a 28 spline axle. i know the whole rear wont swap over since the camaro has a different mounting setup. So i was thinking about swapping the guts over, but i think the axles are a different length, and im not even sure if its bolt in to the 7.5 housing. can anyone verify this?
question about 7 5/8 rears
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switching from 2.41 to 2.74 isnt worth the effort
it wont be that much difference from where you are
what trans do you have in the car? my buddy has a th350 and 3.42 and its a pretty decent around town and on the highway
i was gonna go with 3.73's in my regal, but it had the OD trans, dunno how they'd be on the highway without the OD
that being said, i believe the ring/pinion would work, but if it were me i'd look out for something with a more attractive ratio
it wont be that much difference from where you are
what trans do you have in the car? my buddy has a th350 and 3.42 and its a pretty decent around town and on the highway
i was gonna go with 3.73's in my regal, but it had the OD trans, dunno how they'd be on the highway without the OD
that being said, i believe the ring/pinion would work, but if it were me i'd look out for something with a more attractive ratio
SBCregal said:
3.73 without OD would be horrible on the highway.
i wouldnt go higher than 3.08 or 3.23 without an OD and the 3.23 even then is a gamble.
i myself have a 2.41 gear and i plan on upgrading to a 3.08 at the least but maybe a 3.23 since the car doesnt actually get driven on the highway at all. its a street car and usually doesnt see over 55 MPH.
let me give some numbers based on 2.41 gears, 3.08 and 3.23.
at 60 MPH with a 25.5 inch tall tire and no overdrive the 2.41 gear gives an RPM of 1905. the 3.08 gives and RPM of 2435 and the 3.23 gives an RPM of 2554. not much difference between 3.08 and 3.23 but IMO the 3.23 would suck up more gas while giving little more performance than the 3.08 would.
ive run my car on the track before and to say 2.6 second 60 foot times is BS is a fair statement. this 2.41 gear just sucks all around. my plan is to run an OD transmission and use a 3.42 gear BUT to keep things cheaper i may have to keep the th350 and use a 3.08 gear. an OD trans would allow me to have better torque multiplication than a non OD trans but given the current number is just under 6 and adding a 3.08 gear would bring it to 7.5 torque multiplication would be better than it is now which i guess i could live with. an OD trans would let me have it near 8.3 with a 3.42 gear and a 3.73 would take it to 9. even small increases in gearing can produce big gains but that OD can bring down the RPM to give better fuel economy.
i think it is well worth comparing what the car is doing most of the time (daily driver with little if any highway use for me) and matching the gearing with the engine (stock mostly ATM) as well as the transmission (th350) and comparing the total torque multiplication numbers (2.45 x 3.08= 7.5 Vs 2.45 x 2.41= 5.9) to the rule of thumb for gearing and performance (up to 9.5 or so for street use and 10 and higher for race only) will help you figure out what gear you might want to use.
i've figured for a non OD trans ill probably use a 3.08 gear. the extra tooth for a 3.23 wouldnt justify the extra RPMs IMO as im simply trying ti improve launch only some. i just want something lower than a 2.6 60 foot time for once.
I ran a 241 open ended diff for a few years and loved that ratio on the highway. I have 342 posi in there now and it's not terrible on the highway but it rev higher than I'd like so I have a 308 posi that I'm planning on putting in with a T5 WC transmission and a vortec 350. 308's were real common a few decades ago but GM had to put taller gears into their cars since the hp of the engines were dropping during the smog years.
as far as the 7 5/8 rear end it will fit in a 7.5 housing and if it's a 28 spline then you'll have to find some GN axles.
as far as the 7 5/8 rear end it will fit in a 7.5 housing and if it's a 28 spline then you'll have to find some GN axles.
i appreciate the info, i have a 200 4r for the car, and as i will be doing alot of highway driving, i want something that will keep the revs down but launch good, im thinking either 3.23 or 3.42 gears.
for the 7 5/8 carrier I'm not sure where the division is for a 2 series carrier and a 3 series. For a 7.5 308 and down use a 2 series and anything taller than 308's use the 3 series.
supreme_eighty5 said:
go with 3.42 or 3.73 gears. 3.23 shouldnt even be an option with an OD trans. the OD gear will more than make up for a shorter gear like a 3.73. and you will get better launches with a 3.73 or a 3.42 over a 3.23 any day.
you also have to consider what the engine RPM will be like with the gear and OD as you will be cruising around using the OD gear of .67. with a 3.73 gear your cruising RPM at 70 MPH will only be 100 RPM higher than if you had a 2.41 gear and a th350. at 3.23 it will be lower and 3.42 will be about the same.
i think the 3.23 gear would be too high (numerically low) for a 2004r. use the 3.42 as the minimum gear for that transmission. if you were running the 700r4 i might say 3.23 as the first gear ratio is pretty low (numerically high) compared to the first gear for the 2004r and its OD gear (.70) isnt as good as the 2004r's OD gear (.67)
go with a 3.42 or 3.73. trust me. you'll be happy with either.
pontiacgp said:
i think its the same for both but im not sure. did fbodies get crappy gears like 2.41 too?
G_Body_Enthusiast said:
I know they put 2.73's in them with the 700r4, not sure if they put any higher ratios than that.
here's what I found looking for the ratios that were available in F bodies..
41 : 15 = 2.73
41 : 14 = 2.93
40 : 13 = 3.08
42 : 13 = 3.23
41 : 12 = 3.42
41 : 11 = 3.73
41 : 15 = 2.73
41 : 14 = 2.93
40 : 13 = 3.08
42 : 13 = 3.23
41 : 12 = 3.42
41 : 11 = 3.73
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