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TRANSformation
Third gens can't handle awesome amounts of power, but on the other hand they don't really need to, most of then came with 700-r4 overdrive automatics. And the third gen weighs about 500 lbs more than its bigger brother the 1st gen. The 700 has a very low 1st and 2nd gear and a very high final gear, so in turn you get coffee spilling acceleration and good fuel mileage. Some professional builders can build them to handle 450 lbs torque. But for the more budgeted builder a shift kit will suffice, good for up to 375 lbs torque (depending on application some people put them behind 400 foot lbs small blocks all the time).
There were some 700s that weren't the best choice for a hot-rodding application. If you are doing a retrofit or putting a 700 where there wasn't one, stay away from the ones made from 81-86. These gearboxes were only mediocre at best. The best pick of the litter was the 87-93 units they were upgraded with better pumps and just plain better parts throughout. While the 700 have a reputation of being a weak link, it can take more abuse than you might think. Most 700r4s (except the corvette) had a very "slushy" (soft feeling) shift; a soft shift is actually worse than a firmer shift. When the transmission takes a long time to shift from gear to gear it builds up immense heat, heat is the worst enemy of performance. The transmission takes a long time to shift because the bands are slipping, slipping makes friction, friction makes heat and so on. Anything you can do to make a shift feel harder (assuming you haven't screwed something up) will be better for the transmission.
As I said most not all 3rd gens came with a 700r4, some of these cars came with either a 4-speed or a 5-speed manual, neither one of them will hold up to more than about 250 horsepower. And the dreaded th350-c this tranny was a dud plain and simple, anything more than a v6 will turn it into cheap impression of an atom bomb. However if your 3rd gen has a 5-speed you might be able to swap in a T56 6-speed manual without too much trouble. Unfortunately there isn't much of a way to "beef up" a manual transmission. So if you have a manual in your 3rd gen, swap it out for another tranny.
Torqued off
If you have a motor that has a power band that doesn't start until 2000 rpm, you will need a torque converter with a stall speed of at least 2000 rpm. If you have a torque converter with a stall of 1800 rpm your car will leave the line 200 rpm before it starts to make good power. With a 2000 rpm stall converter you will leave the line only when the converter is turning at 2000 rpm. This will make you leave the line when your motor is closer to its peak power. This will make your E.T.s lower, isn't that what we all strive for in the first place?
You will also need to match your gears to the power band and the torque converter. We need to make up a motor; lets say a 350. On our imaginary engine we will have a big cam, good heads and all the other speed goodies. Our motor makes 368 hp @5600 rpm, and 385 lbs torque @ 5800 rpm. The power band is between 2100 and 6100 (pretty wide) and this wicked motor is between the fenders of our imaginary 85 'bird. We also have a 700-r4 with the appropriate torque converter (2200 stall) we will need some gears that mean business. Probably 3.25:1 or better maybe even like 3.43:1 this will aid in the effort of acceleration. If say 3.08:1s were used with a stock stall converter this thing would be slower off the line than it would if it had proper gears and converter. If you have a higher rpm cam (i.e. one that has no low-end torque), the low 1st gear on the 700r4 will help you accelerate with out loosing cruse ability. If you have a hankering for new gears, ask the manufacturer what the best ratio would be with your combo of parts. I can't stress this enough, your components MUST match or it's all worthless. Your sinister fender shaking idle might impress or even intimidate some, but without the proper gears, converter and other components your little sisters 68 VW beetle could beat you into submission, so pay attention.
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