The 1962-1967 Chevy II and upgrades.
The Chevy II was an economy. It is fun to fix up these cars and make performance vehicles out of them. Also driving demands have changed in 50 years. Some things to consider when fixing up your Chevy II.
The stock front is notorious for not holding alignment. New parts and a knowledgeable alignment shop and the car should hold alignment. Problem is most alignment shops don't understand the car if it isn't on their computer today. If you keep the stock front end setup, do you know of an alignment shop that works with the muscle cars? One that can tell you what shape you are in.
Stock style rubber bushings are recommended on the front drag links. New poly-whatever tougher/stiffer ones may cause the drag link to flex instead. This can lead to a break in the drag link and loss of control.
If staying with the stock front clip, then the CPP mini sub frame kit is the first non stock mod I would recommend. Lower arms only for me. Turns it in to a double A frame. Similar to most cars with more durable suspensions. If going on to the next step in the future, get the ones with the special bend to clear the rack & pinion steering.
Sub frame connectors also help a lot on these cars. These were early unibody designs. They tend to flex more than I like in the stock condition. I used a weld in set from Global West. They are great at keeping the flex down and helping the suspension to work better.
Next step for me was the Church boys Rack and pinion. 2 primary gains. Better steering feel and response. Also no special notched oil pan needed. The notched pans have less ground clearance. I have torn the bottom out of one of these low hanging pans on our not so well maintained streets.
Front disc brakes of course. If you are going to go fast, you got to stop just as fast.
Automatic transmission, get with a good performance transmission shop and they can tell you if they can build a good trans for you. They will need to be built with upgrades to handle higher horse power. I have a 700R4, takes a new rear cross member and the right tail shaft to clear the floor. My transmission is built for 500hp. Should last a long time with my 350hp.
Don't forget the drive line. If going beyond 350 HP forget the stock one, get a good aftermarket one rated for the torque. And drive shaft loops. These are for safety. A drive shaft flying around can do major damage.
Headers are always fun, but getting the ones you want to fit well, miss all the bits and be affordable can be a challenge. From experience a dual exhaust may make life easier working on the car. Its up to you.
If still a stock gas tank and gas line is it 5/16? Bigger line may be needed if you keep your foot in it for more than a couple of seconds with 400+ HP.
Safety, upgrade your seat belts to a 3 point at least. We have learned a lot about safety in 50 years.
Want lots of HP? consider a roll cage. With 400+ hp you will only be able to run on most tracks once, you will need a roll cage the second time. Lets face it, no car is designed to run at faster than freeway speeds and protect you. A cage is needed if you want to go fast.
What does it cost? My rule of thumb on cost vs. horsepower. up to 375 hp, all about the same final cost. Up to 450 hp 2x cost of 375hp, up to 600 hp 3 x cost, more than 600 hp a big sucking sound, as much as you can throw at it. HP in the engine is easy. Building the drive train and suspension to survive is the trick. These cars were not designed for high horse power. Major upgrades will be needed to handle more than 350 HP.