1970 Pontiac Trans Am - Unobtanium

The machine work and distribution was to be handled by Sevakis, technically keeping Pontiac out of the crosshairs of the GM Corporate brass. Chevrolet could, of course, run its own Sevakis-machined block through its parts network, but that's another story altogether.

With a price tag of $2,000 for a complete block with main caps back in '72-'73, they were far too expensive to be commercially viable. That was a serious chunk of change back then, about $10,000 in today's money, according to the Consumer Price Index inflation calendar.

About 10 blocks made it out of the factory before the program ended. According to Alex Hiller, a former Pontiac prototype technician, approximately 100 of these blocks were cast at the factory, though most were scrapped due to cracking of bores and mains during testing. Head sealing was also a problem, particularly with the larger bore sizes. A racing boat engine he built using the same block came apart in a similar fashion. Former Pontiac Special Projects Engineer Tom Nell confirmed that 10 blocks made their way to Sevakis before Special Projects was closed down. He lost track of them after that and ended up leaving Pontiac altogether, opening a successful bike shop in the suburban Detroit area.

It doesn't appear that Sevakis actually delivered more than one or two finished blocks to customers, as at least six unmachined units have popped up over the years. A fully-prepped block was pictured in an Aug. '72 Car Craft article, however.

Greg managed to hunt down one of those unmachined blocks (casting date January 7, 1972) and purchased it from Pontiac Heaven's Steve Barcak. It was in exactly the same shape as when it was popped out of the mold, so it was sent to Kauffman Racing Equipment, who fully machined the block, which was then treated to a special salt bath to preserve the aluminum. The bores were sleeved to a final bore size of 4.155 inches. The sleeves actually correct the majority of the cracking problems originally experienced during testing, as the cracks generally originated in the bore area and quickly spread.

Meanwhile, Greg found a Ram Air V-headed 455 Super-Duty originally built by Bill Foder. It was on eBay and coincidentally, just a few miles from his house. It was complete, and in lieu of a factory intake, was topped off with a steel tubing Wenzler Ram Air V tunnel ram.

He won the auction, brought it home, and disassembled it. The SD block and intake went back on eBay and the aluminum block, Ram Air V heads, and the rest of the componentry liberated from the eBay engine were sent to noted Chicago-area Pontiac racer Rick "No Sponsor" Johnson, who handled the building of this unique Pontiac powerplant.

The engine that emerged from Rick's shop is a true one-of-a-kind, featuring some of the rarest castings ever to come from Pontiac. The block was filled with a set of Diamond custom 4.155-inch, 10:1 forged pistons with a 24cc dish. Total Seal rings were used, file-fit to each piston. They swing on Eagle H-Beam 6.700-inch 4340 rods with 2.200-inch rod journals and a Crower billet 4.5-inch stroker crankshaft with 3-inch main journals.

Federal Mogul bearings were used throughout. Additionally, a 60psi Melling oil pump and a Canton street/strip oil pan keep the lubricant under control. Total displacement checks in at 488 ci.

The casting No. 44 Ram Air V heads are unported, as they flow almost too much in stock form. They were rebuilt by Rick, using 11/32-inch stem REV tuliped, stainless steel valves, measuring 2.19 inches for the intake and 1.73 inches for the exhaust, the stock Ram Air V valve diameters.

These valves are actuated by a Comp Cams solid-lifter camshaft with 274/274 degrees duration at 0.050-inch lift and 0.675-inch lift with Crane Gold 1.65:1 rocker arms. It is ground on a 112-degree lobe separation.