One day he came across an article on the GM Performance Parts Ram Jet 350, in which it was noted how the engine was designed to look similar to the early Corvette fuel-injected mills. This plug-and-play, turnkey setup supposedly required only that a fuel pump be installed in the gas tank. Well, maybe.
"My only concern was that from the pictures it appeared that the [FI] doghouse would be too high for the hood," Walker observes. Turns out that his initial assessment was correct. When he contacted GM, he was told that the Ram Jet 350 would require a hood modification in order for it to fit in a '78 Corvette.
Then VETTE magazine offered a potential solution, by featuring a '79 model with a C5 powerplant. Walker called the shop responsible for that project, and the manager put him in contact with another customer who had just dropped a Ram Jet 350 into his '78 Corvette.
After an hour of discussion with the owner of the car, and later reviewing photos of the project, Walker became convinced that he should arm his Pace Car with a whole new level of firepower.
Fortunately, prior to his decision, he had already installed a 700R4 overdrive transmission rated for output levels of up to 500 hp. This trans dropped the engine revs by 1,000 at 60 mph and allowed for both faster acceleration and improved fuel mileage.
3 Some buyers paid exorbitant dealer markups for the
Walker then assigned himself some more detective work, searching the Internet for a good price on a Ram Jet 350. He found one listed by a car dealership for $5,000 or "best offer." Being a streetwise cop, he low-balled the dealer and got it for $4,000. He then took it to Doug Johnson of Bar Racing in Maryland Heights, Missouri, who agreed to take on the installation.
While Walker reports that it was a largely straightforward job, squeezing the Ram Jet into the '78 did require some modifications. The oil pan had to be switched out for clearance, while the aforementioned replacement fuel pump had to be capable of an operating pressure of 43 to 55 psi. Walker used a pump designed for an LT1 Camaro/Firebird, along with a 3/8-inch return fuel line.
In addition, Just Corvettes, owned by Dan Hughes of St. Charles, Missouri, provided a 1982 fuel-sending unit that Walker modified to accept the correct fuel pump. (The newer unit already has the wiring in place for the pump.) Walker points out that on '78 Corvettes, it's possible to remove the sending unit without dropping the gas tank. It only goes in and out one way, however, so you need to take your time.
GM also recommends using its heavy-duty starter (PN 10496870 for 12-3/4-inch flywheel/flexplate or PN 1876552 for a 14-inch flywheel/flexplate) as part of the swap. Again, Just Corvettes was able to provide the proper unit.
The computer for the Ram Jet is very small and can be easily secured on the firewall. An O2 sensor also has to be installed on the left exhaust pipe, right below the exhaust manifold. While GM recommends headers, Walker found that the original exhaust manifolds worked nicely and required no modifications, saving both time and money.
Once the Ram Jet was installed, it started up without any problems, but one issue became apparent right away. From time to time, the engine would run hot. Turning up the heater corrected the problem, at the cost of broiling the occupants' legs on hot days. Turns out you need to run a bypass hose from the water pump to the intake manifold, a modification not listed in the Ram Jet installation manual. Walker's astute detective work, along with a simple 6-inch piece of hose (never, ever used for getting miscreants to confess) solved the overheating problem.
As for the clearance issue on the top of the engine, even though he had spoken at length to someone who had installed a Ram Jet 350 in a '78 Corvette, Walker admits it was still a little stressful closing the hood for the first time. A ball of clay showed a mere half-inch of space.