Trick Flow Specialties 347 Stroker - Bigge-R Is Bette-R

The kit included the heads, cam, upper and lower intake, valve covers, roller rockers, head bolts, complete gaskets set, timing chain and new pushrods. The Track Heat intake system turned out to be a better choice for the smaller 5.0L, but we longed to try the high-rpm TFS R intake on a bigger 347 combination. In Part 1, the Track Heat was teamed with the wildest cam we thought might fit using the stock 5.0L pistons (PN TFS-51402001). The hydraulic roller cam offered a 0.542/0.563-lift split, a 224/232- duration split (at 0.050), and a 112- degree LSA.

Powerful even with the Fast-as-Cast 170cc Twisted Wedge cylinder heads, we upgraded our kit with a set of new 185cc Street Port Twisted Wedge Heads. Designed to offer a cost savings over the full Competition porting, even the new Street Port heads were overkill for the 302. The Street-Port heads and TFS R intake combination deserved more motor, and since bigger is obviously better, we decided to run this second test on a larger 347 stroker.

The Track Heat engine kit improved output of the stock 5.0L from 259 hp and 320 lb-ft of torque to 377 hp and 356 lb-ft of torque. No matter how you slice it, 118 hp qualifies as a serious power gain.

Impressed as we were with the results of the Track Heat engine kit on the 302, the output of the modified 5.0L was nowhere near what the Street-Ports head would support. Combine this with the fact that the TFS R-series intake combo was designed for increased displacement and engine speed, and you have the beginnings of our sequel to the Track Heat test. To complete the story, all we had to do was toss in an extra helping of cam, compression, and cubes.

With that in mind, we selected a 347 stroker, replete with forged internals from Procomp Electronics and Probe Racing. Procomp Electronics supplied the 4340 forged steel crank and matching 5.4-inch rods, while Probe Racing came through with the forged flat-top pistons that included valve reliefs for both TFS and inline valve locations. L&R Automotive was responsible for the balancing, stroker clearancing, and assembly of the short-block. When all was said and done, the forged 347 was ready for almost anything.

We also installed a wilder cam profile. The TFS cam originally supplied with the Track Heat kit was plenty powerful, but we wanted to show that the new 185cc Street Port Twisted Wedge Heads had plenty of power left in them on the right combination. To illustrate this, we combined the additional displacement of the stroker with an XFI cam profile designed specifically for stroker applications.

The XFI236HR-14 cam combined 0.579 lift with a 236/248-duration split and a 114-degree LSA. A tad on the wild side for a street 5.0L, the XFI profile was tamed somewhat by the additional displacement offered by the 347. It was installed using a set of hydraulic roller lifters and double-roller timing chain from Comp Cams. The Street Port heads were installed using ARP head studs securing Fel Pro 1011-2 head and 1262 intake gaskets. The bottom-end was secured using a Milodon oil pan, pick-up, and windage tray, while induction chores were handled by an Edelbrock Performer RPM Air Gap (the single-plane Victor Jr. resulted in no additional power) and Holley 750 HP carburetor. We finished the stroker with an MSD billet distributor, Meziere electric water pump and Hooker headers.

As always, the 347 stroker was given a thorough break in prior to running in anger. Jetting the Holley carburetor was made easier with the Percy’s external Adjust-a-Jet system. After timing sweeps indicated that the optimum timing was 35 degrees, we were rewarded with peak numbers of 482 hp at 6,600 rpm and 424 lb-ft of torque at 4,900 rpm. The extra displacement, cam, and compression illustrated their worth by offering a broad torque curve, bettering 400 lb-ft from 4,800 rpm to 6,100 rpm. This compares to 376 hp and 355 lb-ft of torque from the 5.0L tested previously. The original TFS-headed 5.0L managed to exceed 333 lb-ft of torque from 4,000 to 5,900 rpm, but neither the peak nor average torque production could compare to the stroker combination. Though we still had yet to max out the capacity of the 185cc Street Port Twisted Wedge Heads, this test clearly illustrated that when it comes to performance, sometimes bigger really is better.