I have a 1969 Camaro RS convertible.I'm thinking of putting a supercharger on it and was wondering if anyone could tell me what's the best one on the market for a Built Carbureted 400 Small Block Engine.Which one will give me the most horsepower&torque.My motor is pushing about 420 horsepoweras of now.

You will need to provide more information. Compression ratio? Cam specs? Forged pistons? Forged crank? What rods?

What type of supercharger are you thinking about? Roots or Centrif.

Generally speaking you want your compression 8.5 or lower (there are exceptions), you want your cams LSA in the 112-114 range. Depending on the power level/boost you might need forged pistons, better rods and crank. If you give a little more info I/we can get more specific with advice/recommendations. What will the car be used for? Are there any other mods to the car?

I was thinking of a Vortech Supercharger.I'm not to sure because I bought the car just like it is,but I think it has a 290 Cam,forged pistions,it has Aluminum Heads,not sure about crank and Rods.I know it has MSD Ignition,MSD Distributor,MSD Spark Plugs and Wires,and A 3000 Stall.The Engine is Bored either .30 or .60 over.

With the limited information you have you will have to do some research. Your LSA (lobe seperation angle) of the cam is very important. You really don't want to guess on any of these things (compression, LSA, crank and rods). If you want to really make power and have the engine live and run on pump gas all these details have to be on the money. Sure you can bolt on the supercharger and it will make more power than you have right now, but if you have the wrong cam you will just blow all your boost out the exhaust. We also don't know what your piston rings are gapped at. It they are too tight adding boost (and more heat) to the cylinder can cause the rings to butt, this will break your piston/s. If you can contact the previous owner, and find out where the engine was built/bought. You may be able to get the info needed to see if your current engine is a decent candidate for a blower.

If your compression is too high you will detonate and ruin the engine. Your best bet is to go ahead and build or buy another short block, with the right parts. That is the only way to get the most out of a blown/supercharged engine. Built id so you have ~8.5:1 compression, forged pistons, good rods and crank. Then add a cam with 112-114 LSA (slightly more exhaust lift/duration) to help clear out the cylinders (very important with blown engines). Spending $3000 on a blower kit and only being able to run 2-4lbs of boost is not the best idea, this is why the specs are needed.

One thing I always suggest when someone is thinking about playing with a blower/supercharger for the first time is to grab a copy of the book called "Street Supercharging" by SA Designs (Summit carries it as well as many book stores). This will give you enough information to give you an idea. It doesn't cover everything and it is very conservative. It will give you enough info so you will be able to ask the right questions for your application. I read every book, magazine article, talked toblower shops and guys with blowers, before I built my blown engine. You will find out you might get 5 different answers to the same question if you ask 5 different people. There are many different schools of thought when it comes to supercharging. The basics I outlined above (cam, compression, etc..) are fairly coonstant accross the board. Things start changing when you talk about amount of boost, timing, quench, etc... that's when people tend to have different thoughts of what is "best".

I know I didn't answer your question exactly, but I woul rather you find the information and answer the question for yourself. What I mean is I could say throw a Vortech on there and it will be fine. The fact is that's not 100% true. If you don't know your specs you would be better off building a new engine specifically designed for boost.

7d's right!

Most guys build dedicated blower motors b/c of all the "BAAAAD" things that can happen if too much boost is created.

Of course, mild motors can AND do live under mild boost if that's what you want?? But it doesn't sound like it..

I think I read once where the stock limit is only like 125hp or so more?? AND this is holding the rpm's to stock levels up top too...

pdq67