Once the dyno testing was complete we moved forward with some necessary upgrades to the drivetrain including a new clutch, a rebuilt transmission, and a new aluminum driveshaft. In anticipation of the 150-mph top speed, we installed a 13-inch disc brake kit from Baer with six piston calipers as well as a rear disc brake kit from Doctor Diff. With the chassis upgrades complete, the car was sent out the door for some quick shakedown runs around town.
The engine idles smoothly at 900 rpm due to the low overlap camshaft and the small carburetor, but the airflow capacity of the heads and intake allows it to pull hard past 6,000 rpm. Even with 2.94 gears in the rear, the car went sideways anytime we stomped on the gas. After a few break-in miles on the street, the car headed out to Portland International for a track day. We had a few teething problems at the track with the oiling system so the session ended early, but in the few laps that Tim was out there, he was able to push the car up to about 150 mph on the back straight. The engine was making enough power to push the car hard down the straights, and the brakes were good enough that he could delay his braking points a little further than last season.
Next steps now are to refine the oiling system and to tune the chassis a bit more. This drivetrain with the aluminum heads, lightweight clutch, and aluminum transmission is about 100 pounds lighter than the previous drivetrain. Taking 100 pounds off the nose of the car means that the suspension needs to be tweaked a bit to get the car back into balance. We already have a bunch more parts on order so stay tuned for an update in an upcoming issue. mm
About the Author: Andy Finkbeiner is the author of How to Build Max-Performance Mopar Big Blocks published by CarTech. Andy also owns AR Engineering, a company that specializes in designing and manufacturing parts for Mopar muscle cars.