Once you have built that big bad engine for your muscle car, you’ll need to be 100% sure that a few other things match the engine that you just built, this is another one of those times when you need to think about what it is you want the car to do, is it a daily driver, or a race car / show car.
What you use the car to do will change the set up of things like the rear end, suspension, and transmission immensely, you can divide the two things evenly, but it usually doesn’t work very well to put a race engine on the street as your daily driver.
To get lower ET’s at the drag strip the racers are usually running a low rear end gear, or ring and pinion set to lower their time when they run the ¼ mile, and the lower the rear gear, the harder it becomes to drive the car on the street every day.
Most of the real racers are running a gear set that has a 4.30:1 ratio or a a lot lower, while most street cars don’t run a gear lower then 3.73:1, as a matter of fact it’s more common to see even higher gears then that on the street, like 2.90:1.
Obviously the lower the gear in the rear end of your car, the harder it will be to take your car on the freeway around your city, the engine will rap out at a lower rpm, but this is ideal for a race car, when you build your engine, get the company that you buy your cam from to recommend the right gear set.
If you do what they tell you you’ll get much better results with your car, but the gearing in the rear end is not the only thing to consider, if your running a four or five speed transmission in your car, you should know the first gear ratio, is it 1:1 or less like .85:1 or .90:1 this will help you also.
If your running an automatic transmission you’ll need to match a stall converter to your cam shaft, which means that you need to look at the power band of your cam shaft, if it runs from 3,000 rpm to 6,500 rpm, then you’ll need a converter that stalls at 3,000 rpm.
Let me give a very basic explanation of stall, with a standard transmission you’d have a clutch so you could get your car to it’s power band before stepping off the clutch pedal, a stall converter does the same thing for an automatic transmission.
But it has some draw backs, your car won’t drive normally until you hit your transmission stall speed, it will seem like you don’t have the power that you should, or seem doggie, these are reasons to build a street engine for the street, rather then a race engine that you drive on the street.
You can’t have the best of both worlds, and expect your car to be reliable for every day street driving, you can build a street / strip car, but you’ll always give up some of the good reliable street habits of your car when you do, you’ll always have to give up something to gain power in your engine.
I’ve been in the automotive business for about 20 or 25 years, I have worked in all facets of the industry, from parts to restoration, all different makes and models, I just want to keep people interested in the old cars because it’s where my heart is.