Over the first three installments of this story, you learned that Jason Korb of Middletown, Pennsylvania, wanted to rebuild the Pontiac 350 engine in his '69 Firebird for more power and easy cruising, but he didn't want to give up driveability or break the bank to do it. He contacted RaceKrafters Automotive Machine in Lancaster, Pennsylvania, where Bob and Craig Wise scienced out a combination to suit Jason's requirements.
HPP followed the build-up from beginning to end. In Part I (June '08) we covered the machine work on the bottom end and the porting of No. 17 small-valve heads and larger intake valve swap to improve power, while avoiding the higher cost of new heads. Part II (July '08) took us through the assembly of the engine and illustrated where upgrades were made and money was saved without compromising quality. Then came engine dyno testing in Part III (Aug. '08), where the 0.030-over 350 produced 342 horsepower on RaceKrafters' in-house Stuska engine dyno.
Following the engine dyno session, Jason, a professional mechanic by trade, installed it into his beautiful '69 Firebird with the help of his son, Andrew, and wife, Ann. The value of investing in engine dyno testing proved its worth when, after tightening the final bolt, Jason turned the ignition key and the 350 jumped to life without any hesitation and nary a turn of the starter. He told HPP, "The engine started so quickly that I got scared. I expected it to at least crank over a few times." This fresh Pontiac 350 ran great and a drive around town proved that it was a sprightly performer for its small displacement.
Already equipped with 3.90:1 rear gears, after the first run on the highway, the Korb family agreed that if they wanted to use the car for the intent that it was built, either an overdrive transmission or milder gears would need to be installed. At 65 mph, the little engine was screaming, which makes for not only a high rate of wear, but poor fuel mileage as well.
The decision was made to install a 200-4R four-speed automatic transmission, along with a 2,200-rpm stall speed torque converter and a Fourth-gear-only lock-up. HPP wasn't present for the transmission swap, which Jason performed in his home garage. He stated the kit he purchased from Gear Star-which included a crossmember-fit and worked as represented.
With the engine's highway rpm now under control, HPP joined forces with the Korb family and the crew at RaceKrafters to put the final tune on the Firebird via the in-house DynoJet chassis dyno-just in time for the summer cruise season.
The Korb family did a beautiful...
The Korb family did a beautiful job of installing the 350 Pontiac. With the gloss-black engine compartment, we can now understand why Jason painted the block the color he did instead of traditional Pontiac Silver Blue Metallic.
A proper chassis dyno session...
A proper chassis dyno session includes accurate air/fuel ratio data. To obtain this, an oxygen sensor bung was welded into the header collector. A wide-band oxygen sensor is part of RaceKrafters' dyno.
The wide-band oxygen sensor...
The wide-band oxygen sensor has the ability to accurately read an air/fuel ratio of 10.0:1 to 20.0:1. In contrast, a production OE sensor is only accurate at 14.7:1 air/fuel ratio. Anti-sieze compound is applied to the threads prior to installation. After testing, a plug is threaded into the bung.