gear ratio

Q: My 1967 GTO has a 455 Pontiac powerplant with Edelbrock 87cc heads, .030 over Ross pistons, Total Seal rings, Eagle rods, a Crower cam (int./exh. duration 248°/252° @ .050″, lift .512″/.524″, lobe separation 112°), 1.5 ratio rocker arms, and Clevite bearings. The engine was shop built and balanced, and is also equipped with an

I see where Summit Racing lists a TCI transmission that was originally a 4L80E – but they list it as a six-speed transmission. I’ve heard a little about this—did they add two more gears to the transmission? How is this different from the GM 6L80E transmission that is used in the Corvette or in the

Because different transmission gear ratios can greatly affect a drivetrain combination, it’s important for anyone performing a transmission swap to know the gear ratios of the gearboxes you might be installing in your vehicle. We’ve assembled a variety of manual gear ratio charts for General Motors vehicles that we hope can help you avoid choosing

Q: I recently replaced the 305 engine and TH-200 transmission in my 1985 Monte Carlo for a 350 with a mild cam and a TH-350 transmission. My question is about the tranny. It was in a friend’s strip car, and had about 15 passes on it before I got it. The transmission has some kind

I have a ’72 Chevelle and I am planning for either a 700R4 or maybe a 4L60E. The car right now has a mild big-block 454 and I’m looking to put together a nice running street and highway car. I don’t drag race this car but I do want to be able to cruise down

LAS VEGAS, NV — Aftermarket parts maker Dana Spicer used the 2016 SEMA Show to introduce a variety of new products, including drivetrain components for the 2015 Ford Mustang. Summit Racing caught up with Dana motorsports manager Randall Speir at SEMA, where Speir introduced us to Dana’s new bolt-on aluminum driveshafts and new ring-and-pinion gear

Got questions? We’ve got the answers—the Summit Racing tech department tackles your automotive-related conundrums. This week, we’re nailing down the right combination of tire size, gear ratio, and torque converter stall speed for a Pro Street Plymouth. C.C. Governors Island, NY Q: I am building a 1948 Pro Street Plymouth Club Coupe for weekend cruising and

The transmission is the little brother of the powertrain. It doesn’t often get the same respect or attention as the engine—until it starts acting up. You’ll most likely see dozens of engine build stories in magazines before you see an article on a transmission. And we spend hours under the hood or around an engine

Got questions? We’ve got the answers—the Summit Racing tech department tackles your automotive-related conundrums. Last week, we tackled a rich air/fuel condition. This week, we’re helping maximize some already-potent Mustang modifications with larger fuel injectors and airflow upgrades. M.T. • Frackville, PA Q: I’ve been upgrading my 1989 Ford Mustang LX for quite some time. It