EL CAMINO 78-81 vs 82-up rear ends

[SS_Malibu]

I too have the 7.5 posi rear end with freeway gears. We can easily do 85 on the freeway here. The rear gears won't be changing until a 4 speed automatic goes in. Unless the new motor breaks it first.

 

[Kratos]

I just want to weigh in for a minute. My 85 cutlass 442 is running a 7.5 from a junkyard cutlass with 26 spline 3.73 gearset from an early 80’s S-10(ring, pinion, diff) with a mini spool. It runs mid 8’s 1/8 and has gone 13.16@ 104+. In the 1/4 this is three seasons of racing. I don’t “shock “ the drivetrain on launch. I foot brake and bring it up to around 2000 rpms. I have heard that they can handle 400 hp safely. Building the next one with 28 spline axles. (The 8.5 is tucked safely away until I am making big power)

 

[08Malibu]

I actually had 3.42 gears in my 84 Cutlass. They were a really fun gear but I hated the rpms at highway speeds. Now, the engine didn't care but my ears did.
The 350 I have is a nice warmed over rebuild with plenty of power. Compared to the 2.56 gears, the 3.08 will be noticeable. I want the 3.08 for long drives on the interstates and a little bit of gas mileage. Plus I'm running the original 14 inch rally wheels on it. View attachment 201695

I have 3.08’s in my Malibu. Going from 2.42’s, or somewhere close to that number, was a nice change. A nice balance between pep off the line, and highway cruising, even with a stock 305.

 

[jjjaffo]

I just want to weigh in for a minute. My 85 cutlass 442 is running a 7.5 from a junkyard cutlass with 26 spline 3.73 gearset from an early 80’s S-10(ring, pinion, diff) with a mini spool. It runs mid 8’s 1/8 and has gone 13.16@ 104+. In the 1/4 this is three seasons of racing. I don’t “shock “ the drivetrain on launch. I foot brake and bring it up to around 2000 rpms. I have heard that they can handle 400 hp safely. Building the next one with 28 spline axles. (The 8.5 is tucked safely away until I am making big power)

The chassis dyno said I was putting out 419 lbft of torque to the wheels. At the track I would just smack the gas from an idle and launch. No tire spin with the 2400 stall convertor. What would always make me cringe was when it would shift into second gear. The gear change was always instant and HARD. On the street the tires would chirp but at a sticky track that poor rear end took the brunt of that shift. But yeah, that rear end is still holding up quite well. A sure sign of me getting old here, I bought a new shift kit to tone down that damn first to second shift. Waaay too violent for my taste nowadays. I will not be making the same mistake with the turbo 350 in my El Camino.

 

[jjjaffo]

I have 3.08’s in my Malibu. Going from 2.42’s, or somewhere close to that number, was a nice change. A nice balance between pep off the line, and highway cruising, even with a stock 305.

That's why I picked that gear. I have 2.56's in there right now and it's a pooch everywhere. I did 3.42's in my Cutlass and it revved higher than I liked on the interstate. I know it's a matter of taste for everybody out there, and as I'm getting older it's more about cruising with a bit of pep and still getting decent gas mileage. This is always a balancing act with a 3-speed automatic and everybody has their own bench mark. I'm just not interested in putting an overdrive trans in at this point so for me it's a 3.08 gear.