Impala SS questions

[MikeE24]

I was considering buying an impala and had some questions. The car is a 95. Is the only difference in the f-body lt1 and the imp the heads? I was wondering if a used 4l60e from an f-bod would work in the impala? Any answers or advice is appreciated.

[Wild Willy]

I think there were differences in how the Optispark (distributor) was driven, not sure if the years line up exactly. Caprice/Impala had a different cam, less HP more torque for bottom end grunt to get it moving. They are amazingly fast for a large sedan, and easy to modify for more performance.

They also use the 8.5 inch GM rear that is pretty bullet-proof, at least until you start running drag radials or slicks- The insurance company thinks they are a grandpa sedan, with low rates- ABS, air bags, etc. LOW RATES! Great sleeper vehicle.

[Joe K. 99 Zeee!!]

From what I remember, they're at least on par with the newer Marauders from a 0-60 standpoint.

[Z Ya Later]

I think there were differences in how the Optispark (distributor) was driven, not sure if the years line up exactly. Caprice/Impala had a different cam, less HP more torque for bottom end grunt to get it moving. They are amazingly fast for a large sedan, and easy to modify for more performance.

They also use the 8.5 inch GM rear that is pretty bullet-proof, at least until you start running drag radials or slicks- The insurance company thinks they are a grandpa sedan, with low rates- ABS, air bags, etc. LOW RATES! Great sleeper vehicle.

The Opti was driven the same as the other LT1s for the year IIRC. The cam I believe was the same as well. The difference in HP was the heads (iron vs. aluminum, etc.) and breathing (intake/exhaust).

As for the 8.5" 10-bolt, they'll take drag radials and slick with no problems. Talk with some GN owners that run slicks or DRs.

As for the 4L60E, I believe they are interchangeable. But, it would be a good idea to have the tranny rebuilt and beefed up some before putting it in, even if you're not going to do anything to the motor. Just a precautionary measure IMHO.

[Injuneer]

Wild Willy is correct on both counts....

The vented Opti, with the dowel pin drive was introduced to the Impala in 1994, but not until 1995 in the F-Body/Corvette. The cam was also milder in the B-Body:

1994-’96 350 WITH IRON HEADS - The distributor drive was changed on the iron-headed motors only in 1994, so the front of the cam and the timing gear were changed, too. The cam had a pilot hole that was bigger and deeper (0.500" x 1.0625") and it had a longer (.685") dowel pin that stuck out beyond the timing gear to drive the new distributor. This iron-headed motor was used in the Chevy Caprice, Buick Roadmaster and Cadillac Fleetwood, so it came with a milder cam that improved low end torque and reduced valve train noise. These cams have the long dowel pin and either "600" or "779" stamped on the barrel of the cam in front of the first lobe

The iron heads actually flowed better than the aluminum heads:

HEADS
There were two heads used on the 350, one aluminum and one cast iron, along with one cast iron head for the 265. GM claimed that the original LT1 aluminum head had a 15% increase in airflow as a result of revised port angles and higher port ceilings when compared to the 1991 L98 head. That was impressive in 1992, but the iron LT1 head that came out in 1994 was even better. It flowed 20% more on the intake side and made more horsepower on the dyno.

[Z Ya Later]

Then I stand corrected on the motor. However, I still stick with my statement on the rear.

[Wild Willy]

Yes, the rearends are much stronger than what is on the F-body. Still, when you start dumping several hundred horsepower through them, and get them to hook with slicks, on a car that weighs over 4000 lbs., something will break- hope it is only traction. On the B-bodys, driveshafts, spider gears, - the Auburn factory posi's are junk, too. Not rebuildable- figure on replacing it soon if you get serious about launching it.

Still, a great car to build up, with a long history- the frames haven't changed since the 1977 downsizing. You can tow a house with them. Lots of heavy-duty parts, because of the years of fleet service. Almost a bullet-proof car. Did I say cheaper insurance? I sold my much modified '95 to buy the Z28, and I still miss having a car that scares the ricers. Mine had 4.10's and a shift kit, and could fry the tires any time, any where, even the 2-3 upshift at about 75 MPH- Not as agile as the Camaro, but suprisingly fast over the road-

[Joe 1320]

I owned a 95 Impala, here is what I can tell you. The build quality varies greatly. Issues such as cracking control arms, poor carpet, rattles, fit and finish issues..... remember, this is a run of the mill Caprice with a makeover.

With that out of the way, the car can haul butt. After doing a few mods, mine woke up nicely. Easily obliterating the rear tires at will from low speeds. Once rolling, it pulled nicely all the way up to a drag limited 137. If the mirrors get folded in, you'll get 138. It's a big boat that can move with authority. I just wasn't thrilled with the overall build quality and wasn't about to do a makeover of the interior so it went away after a year. I put 25K miles on it that first year, performance wise it was great.

If you get one, they respond nicely to all the bolt ons like roller rockers, cold air intake and exhaust..... the stock stuff is more restrictive than the f-body or Vette hadware so the gains are a little more apparent. It's the torque that really shines in this ride. The big problem is that it's all too easy to cruise at too fast speeds, it seems to be happiest at 85 on the highway.

[FroSSty]

I think everyone has things pretty well covered. I have a 9C1 police package Caprice and I love it...With fairly minor mods you can get into the lower 14s in the quarter... And have a great family car to boot.

[MikeE24]

Thank you everyone for your responses. I have found one that has a good interior but needs a heater core and the trans feels as though it's about to go south. I think i am prolly gonna go ahead and pick it up for about 4k.