[Marky Dissod]

... best is the T56 with 4.10.

Is 4.30 available for the GM 8.5" rear end? I know about 4.10 & 4.56.

 

[95wagon]

Yup , also 3.9

 

[95wagon]

Perfect gear by reluctor count
27 --- 2.53
26 --- 2.61
25 --- 2.72
24 ---2.84
23 --- 2.96
22 --- 3.09
21 --- 3.29
20 --- 3.40
19 --- 3.58
18 --- 3.78
17 --- 4.00
16 --- 4.25
15 --- 4.53
14 --- 4.86
13 --- 5.23


Theoretical reluctor by available gear
26.56 --- 2.56
23.21 --- 2.93
22.08 --- 3.08
21.05 --- 3.23
19.88 --- 3.42
18.23 --- 3.73
17.44 --- 3.90
16.54 --- 4.11
15.81 --- 4.30
14.91 --- 4.56
13.93 --- 4.88
13.26 --- 5.13

 

[1slow96]

How times have changed

In the "olden days"
highway speeds were typically 70- 75 mph , highway gears were 2.73-3.08 and
high gear was 1-1

Don't forget that back then converters did not lock up.

 

[95wagon]

Which made it even worse.
Used to go on road trips with our mother in the family station wagons.
We would bait mum into pinning the speedo in the new car.
61 Impala wagon
65 327 Pontiac wagon
67 327 Pontiac wagon
70 400 SB Pontiac wagon
Never once did she say ,
It's reving too high

 

[SSandman]

Far more folks with 3.42's wish they'd gone with 3.73's than the other way around.
Same with 12" vs. 9.5" converters.

I don't see how they'd know what they were missing? Much easier to put too steep a gear in and say "man, I miss turning lower RPM's on the highway" than put too shallow a gear in and imagine the car might be faster? by what, a tenth or two at best? Just seems like a pick your poison thing to me.The difference isn't much either way, in performance or highway RPM, so it really just comes down to which you value more and how/where you drive.

I think it depends on what you're used to as well. Before I started driving a lot of late model stuff, 3.73's didn't bother me. these days I feel like i'm in my 70 challenger with 3.91's and a 3 speed when I take my 96 out on the highway with 3.73s and a 26" tire. Most late model 6,8 and 10 speeds are turning barely above idle on the highway and i've gotten very used to that. Of course they make more power and have the benefit of more gears, so there's no real advantage to running a steep gear.

 

[Marky Dissod]

My car came with 2.93. I went with 3.42, then 3.73.
I tested performance and economy of all in real world testing and have settled with 3.42 for my style of driving.
The car felt best with 3.73 around town
but 1/4 mile times were no better than with 3.42.
The deciding factor was gas mileage. 3.73 ate much more gas than the 3.42.

From my admittedly faltering memory of his website:
he did 1.6 roller rockers & beehive valvesprings but did not change the heads or cam
he was also using an S10 torque converter.
His car likely needed more and/or more potent mods for 3.73 to peel away from 3.42.

 

[KW Baraka]

If I said it once, I've said it a thousand times......3.73's are what the Impala SHOULD have come with to seperate it as a true 'performance' car versus the Caprice, Roadmaster and Fleetwood.

You want performance, the Impala with 3.73's all the way!

You want pussification, get a Caprice with the pussified gears. 😒

KW

 

[Marky Dissod]

You want pussification, get a Caprice with the pussified gears.

Any LT1 B- or D-car with 3.73 and no other mods (except maybe a speedo correction?) will get much closer to 154MpH, than any LT1 B- or D-car with 2.56 or 2.93.
If not for 3.73's MILD highway MpG penalty, and maybe needing to upgrade the driveshaft, I'd never suggest or recommend 3.42.

Every 2.56 2.93 3.08 & 3.23 B-car will get better city MpG in the real world with 3.42.
All those 4L60Es would've likely lasted longer too.
For 9C1s WXs (& V4Ps?), 3.73 would've been better - but then GM would've had to upgrade all those driveshafts.
Still I blame CAFE MpG tests for 2.56 2.93 3.08 & 3.23.

 

[Blue Bowtie]

1967 Corvette roadster, 427, 3.08 gears, sponsored by RBC. It did impressively well on road courses, surprising those who thought the "right" thing to do was running a 12-bolt 3.70.

 

[95wagon]

Of subject , more info on corvette please.
" 12 bolt 3.70 " ???

 

[cadejohnson58]

Since we’re talking about upgrades have any of you LS swapped? And are you still happy with your choice if you didnt? My LT1 got roughly 7 mpg this last tank full of gas. Just weighing my options i already have a lt1 block but a skip white rotating assembly for a 383 and thats like $1600, heads and cam another $1600, machine shop im sure wont be cheap so lets say $1000. My buddy who does ls swaps for a living can do a heads and cam 5.3 for $2000 with core or $2500 without and thats just engine but ill be saving money in alot of areas like not having to upgrade to coil packs and ls ecu. Thank you all im sorry for the loaded question

 

[95wagon]

Yup and yup see sig.
If you are going for a proper job , the money goes pretty fast . And for me it was all parts

 

[cadejohnson58]

Yup and yup see sig.
If you are going for a proper job , the money goes pretty fast . And for me it was all parts

Do you have a little list that i can go off of? I know i need KDS mounts, LS1 oil pan, a better trans crossmember, measure for new driveshaft, ls1/6 intake, fuel system updated for corvette filter with built in regulator and do A/N lines for that, and a wiring harness. I think ultimately its the better platform to go with for better power and gas mileage when not stomping on it. Thank you so much

 

[shakenfake]

Skip the vette regulator and go ahead and get an aftermarket one

Also that is crazy you are only getting 7 MPG. Even my massive exhaust leak, code throwing LT1 got 17 to the gallon around town

 

[cadejohnson58]

Skip the vette regulator and go ahead and get an aftermarket one

Also that is crazy you are only getting 7 MPG. Even my massive exhaust leak, code throwing LT1 got 17 to the gallon around town

Mine also has crazy exhaust leaks that drive me crazy. Doesn't throw codes anymore since hooking up EGR correctly. Maybe my trip meter is lying to me one second i saw it over 170 miles then the next it was slightly lower at 168.

 

[shakenfake]

Hand calculate it

 

[95wagon]

Not to state the obvious,
Exhaust leaks before and near after the O2s will kill mileage ( and long term , the engine ) even when they O2s are being ignored at WOT.
Stock calibration will continue to add fuel at at WOT if it was adding just before.

Your LS questions , not a one sentence answer.
Everyone is different
The the Corvette filter has its place in sone swaps, to blindly say use it or dont in an LS swap is , well ,,,
Crossmember, driveshaft depends on engine placement. Mine is different but not due to the swap.
Oil pan depends on engine and placement .
I DONT see a mild build ls swap as saving money over a moderate LT build.
Mine was more of a " just cause "
My LT1 -T56 was a pefectly good heads cam setup .
They live on in other peoples cars.

 

[shakenfake]

It does have it's place but why use it when you can just run an aftermarket regulator? Vette filter is fugly and I prefer some other solutions nothing wrong with it inherently.

 

[95wagon]

-Good regulator 200 or more

-If you have a return style system the stock regulator might be just fine.

Esthetics , for a returnless set up ,the Corvette regulator is on the frame rail ahead of the tire and looks just like the stock filter plus the return which is right there just asking to be cut and have a 8mm quick connect.
Personally , don't think any regulator is terribly attractive. Our race cars the regulators are where they make sense often visible.
My street car completely out of sight.

Lets see yours shakenfake