[rohrt]

Originally Posted by b-man

Several years back I had my choice of 2 cars that I could drive to work, a mild 455-powered (8.2:1 compression, 068 cam) '64 Tempest and a bone-stock 5.7 LS1 (346-cube) '02 WS6 T/A convertible. Both cars had about 350 HP.

1/4 mile times:

Tempest - 13.899 @ 101.85 MPH - traction-limited ETs due to hard radial street tires, tall gearing and lack of a posi rear. Used only 1st and 2nd gear to run the 1/4 mile. Pretty decent MPH for a low-compression engine with a stock '66 Tri-Power, 068 cam and HO exhaust manifolds. Race weight of 4050#.

T/A - 13.44 @ 104.03 MPH - much better gearing for drag racing with a 3.06 low gear and 3.23 rear, still somewhat traction-limited on stock tires but the posi rear helped. Race weight of 3900#.

The 455 (462) Tempest was more fun to drive around town because of the instant torque generated by the 455. The LS1 torque output was understandably lower and would come on later in the RPM range so it wasn't as satisfying when starting off from a stoplight.

On a road trip the T/A was much nicer to drive, fuel mileage was about double that of the 455. The 455 would get 9-10 MPG in town and a best of 13+ MPG on the highway, the LS1 would get 16-18 MPG city and 26-27 MPG on highway trips.

The 455 was backed by a TH400 with a 13" Continental converter and 2.56 gears with a 25.3" tall 235/45-17 tire. The LS1 was backed by a 4L60E (electronic version of the 700R4) with the stock lockup converter and 3.23 gears with 25.6" tall 275/40-17 tires, final drive ratio in OD was 2.261:1.

The tall 2.56 gears behind the 455 were still responsive enough to be fun to drive around town, but no doubt killed some of the city fuel mileage because it required a bit more throttle opening to get the car moving.

I'm still waiting to finish the 430 HP LS3 install in the '64 Tempest as family issues have prevented me from making much progress on it lately. At the same time I'm gathering parts and planning a '64 370 HP 421 HO buildup for my '64 LeMans convertible. The 421 HO engine will be stock except for the camshaft and the compression will be lowered a tad to cope with 91 octane fuel.

I like both Pontiac and LSX engines, they both have their strong points and are great engine designs.

I appreaciate the response.