Part II: Plumbing, Hardware, and Electronics
To recap, in the September '07 issue, Brewer's Restoration and Performance installed its First-Gen subframe conversion kit on the stock subframe of HPP contributor Melvin Benzaquen's '69 Firebird convertible. The net result was not only the addition of rack-and-pinion steering and upgraded front suspension using Global West upper and lower control arms, a QA1 Pro Coil shock system, an Addco 1.125-inch stabilizer bar, and big 13-inch SSBC brakes, but also an engine mount setup that would easily accept an LS1 engine transplant.
At Melvin's shop, Classic Restorations, the subframe was installed along with an LS1 engine and its six-speed trans straight from a wrecked '00 F-body.
In the October '07 issue, an A/C system from Vintage Air was added. We didn't call it Part II because the A/C install is not a mandatory part of the LS1 swap, but we did want to get the A/C story in during the early summer.
Now we will discuss the electronics, linkages, plumbing, and hardware to complete the swap over to LS1 power and six forward gears in this '69 Firebird convertible.
Street & Performance (S&P) provided the proper headers, wiring harness, MAF/air cleaner assembly, and many other parts to ease the conversion. Rock Valley sent a stainless steel fuel tank, replete with an LS1-compatible pump to provide fuel. March Performance supplied an LS1 pulley kit to add style to the front of the engine and alter accessory placement, making it conducive to the swap. Rodney Red's trick aluminum radiator will keep it all cool. Now, let's get to it.
Other Concerns
Measurements will be taken, and a custom driveshaft will be made. Abbott Cable X (www.abbott-tach.com/cablex) converts the electronic signal for the use of a traditional cable to drive a factory speedometer. Or, if you're upgrading instrumentation, a speedo that will accept the electronic output from the trans can be used.
Speaking of gauges, for oil pressure, the oil bypass plug on the oil filter adapter can be removed, drilled, and tapped to accept an 1/8-, 1/4-, or 1/2-inch NPT fitting from S&P. This will allow the sending unit to be mounted without hitting the headers. According to S&P, the rear plug on the passenger side of the head can be removed to provide a place to install the temperature-gauge sending unit. The plug has 12mm threads, but S&P has NPT adapters from 12mm to 1/8-1/4-3/8, or 1/2-inch NPT. Backup light wiring is built into the wiring harness for the six-speed trans.
Conclusion
Though there's still plenty to do to get the Bird road ready, the bulk of the LS1 conversion is complete. Reviewing the work, Melvin said, "The Street & Performance products went in very well. Everything fit, even the headers. All the BRP mods to the subframe were exceptional, too. The March Performance pulleys and Rock Valley tank look great, and even the Rodney Red radiator went in without a hitch. The only modification that required more work (i.e., cutting) than we first thought was the factory six-speed trans installation. I'm not sure if this is because we have a convertible, that the factory trans has more protrusions on the outside than the aftermarket T56, or if it's a combination of the two, but our floor did need surgery to clear the trans." All in all, it was a successful swap that's much easier with components that are now made by these and other aftermarket companies to facilitate the process of bolting an LS engine into just about anything.
