Hi,

The below set up was in my 79 Trans Am 2 years ago. It’s a street car and corresponding street weight. (4,100 lbs with me in the car). With set up below, my ¼ mile ET was 13.43 at 103.89 MPH. 60 ft. 1.71. Launch at 2,000 RPM. Shift points 5,500 RPM. Trap 4,700 RPM. Bias Ply drag slicks on the rear.

1.Engine- 1968 400 Ci. code YS It was machined 30 over resulting in a 406 CU.

2.Heads- #16 Dual Port, intake-2.11, exhaust- 1.77. 1.65 roller rocker arms.

3.Comp Cam- .470 lift. Duration at .006 Tapet lift. Intake 268. Exhaust 276. 1.65 rockers (cam card attached.

4. Edlebrock Performer manifold with a 1 inch spacer.

5. Holley 750 CFM Double pump. Jets- 74 primary, 82 secondary.

6. Hooker Headers- 3 Tube off the head exhaust ports (1 7/8 tube to 4”collectors) .

7. Ignition- Stinger electronic

8. Transmission- TH- 350 with a 2,500 stall and shift kit.

9. Rear end- 3:42 limited slip

10. Electric fuel pump.

Last year I made some changes, noted below, to my powerplant with the anticipation of going faster. With this setup ¼ mile ET 13.84 at 99.3 MPH. 60ft 1.92. Launch at 2,000 RPM. Shift points 5,500 RPM. Trap 4,700 RPM. Mickey Thompson drag radials on the rear. P275 40R 17

3.Comp Cam 472 lift. Duration @ .006 INT 276, Ex 284, @.050 Intake 228, Exhaust 236, Lobe sep 110. New Lift- .519 with the 1.65 rockers. (Cam Card attached)

4. Edlebrock Torker high rise single plane manifold with a 1 inch spacer.

5. Holley 950 CFM Double pump. Jets- 74 primary, 82 secondary. 50cc accelerator pumps

6. Doug Ceramic 4 tube Headers (1 7/8 tube to 4”collectors) with crossover.

7. Ignition MSD 6AL. Timing @ 36 degrees.

10. Electric fuel pump.

Observers- No tire spin. It appeared to bog at launch. I decreased jets to 72/80 with no change.

Why is the car slower?

Solution?