Transmission And Rear Axle
Our objective here is to get the most bang for the buck for our driveline because most of the rest of our money will go into the engine. You have a couple of choices here. A World Class or TKO five-speed can be had new or used, and for not much money. A new World Class T-5 is priced right at under $1,200. The TKO hauls down about twice that amount. We could suggest an old Ford Top Loader, but why? It would cost more to rebuild a Top Loader four-speed than it does to just go with the T-5. If you prefer an automatic, the AOD or AODE makes more sense than that old C4 Cruise-O-Matic. Our message here is efficiency along with speed. We want the overdrive unit so we can go cruising between drag races. Mark's Mustang is fitted with a Lentech AOD transmission with a 3,200-rpm stall converter, transbrake, and overdrive. While this is the best AOD in the industry, it isn't necessary to go 10.79.
A 9-inch Ford rear axle from Currie Enterprises makes great sense because it is reasonably priced. You can go with Ford's C7AW case for both strength and low-cost. Currie also has cases that will handle the twist of a powerful small-block. The most affordable 9-inch path is a four-pinion unit with limited-slip. You don't have to have the 31- or 35-spline axles to crack a 10-second quarter-mile.
When we are car building, thinking about the driveshaft just isn't fashionable or cool, but it is necessary. A good old-fashioned steel shaft works just as well as an aluminum shaft and for less money. If you have the original factory shaft, and it's too long for your T-5 or AOD application, have it shortened for about $150-about half the cost of a new shaft.
The engine is what gets us to a 10-second quarter-mile-or doesn't. How do we build an affordable engine that will crack a 10-second quarter-mile? First, the engine is where you're going to spend most of the $15,000 necessary to blast down the 1320 in 10.79 seconds. You need a rock-solid bottom end that will take the punishment necessary to go 10.79.
Contrary to what bench racers will tell you, you don't need a steel crankshaft to do 10.79-seconds in the quarter. A good nodular iron crank will get you there. Why? Because drag racing is short term. It happens quickly and it's over. If you are going road racing or intend to go 8-seconds in the quarter-mile, you need a steel crank and H-beam rods. To get there in 10.79, you don't.
A solid bottom end is a good investment in many ways because not only will it hold up when the going gets tough, it will stay together when the going is normal for a long time.
Mark's powerplant of choice is a Coast High Performance 347 Street Fighter, an affordable crate engine sporting an SVO Sportsman block (which you do not need to go 10.79), Eagle H-beam rods, Probe 8.5:1 pistons, Total Seal piston rings, main girdle, Trick Flow aluminum heads with 2.02/1.60-inch valves, Anderson B-451 roller camshaft, Harland 1.6:1 roller rockers, Edelbrock Victor Jr. intake manifold, Mighty Demon 650-cfm carburetor, 1000HP fuel system, MSD ignition, MAC 131/44-inch long-tube headers, 3-inch Dr. Gas X-pipe, and NOS Big Shot plate system (200-400 hp).
The foundation for Mark's Coast High Performance 347ci stroker is certainly sound, but unnecessary to go 10.79. A factory 5.0L roller block will get you there with the Coast 347ci Street Fighter package inside. You can get into the basics of this stroker package for under $6,000, if you do a lot of it yourself and shop wisely for parts.