Very specific application...
I'll try to describe fully:

1995 LT1, therefore OBD1

rebuilt as:

383, 6" rod, Forged pistons, H-beam rods & good steel crank (specific brands to be decided)

Iron LT1 heads, stock size intake valves, LT4 exhaust valves, oversized if I can find them.
The usual roller valvetrain stuff, plus a hydraulic roller cam.
Intake ports cleaned up & polished, exhaust ports hogged out (without getting nuts) and polished.

Stock LT1 intake, cleaned up and polished. Inside I mean.

Combustion chamber coated with that special space age material that a lot of folks are using these days.

Finally, I'm trying to achieve a 9.1 DCR.

In summary, I'm specifically building a motor for boost.

Now, this is going to be in front of a 4L60-E with synthetic fluid and a nice big oil cooler.
The engine will have synthetic and a big oil cooler too.

If that tranny blows up I MAY put in a 6-speed, so the gearing situation could change.

The rear end is a 3.08

This is in a Caprice, so it's a bit over 4000lbs.

This is not a track car. It's just for fun and I will definitely want to take long trips in it.

I'm unsure how much boost I want to run, but I'm guessing it'll be about 7 or 8 pounds.

So I could legitimately use either turbo(s) or supercharger.

Either way, I'll be running an intercooler and a good fuel system.

I want the car to be tame if I drive it gently and a monster if I get on it.


So what would you all think would better suit that specific situation, a supercharger or a turbocharger?

 

I guess it would all depend on your budget. If money is not an issue then I would go turbocharger. I say turbocharger because it will be alot easier on your motor for long trips.

 

Forgive me if I'm mistaken, but a 9.1:1 dynamic CR would equal about a 12:1 (or higher) static CR, right? That's way too high for a forced induction motor.

IDOXLR8 is right about the budget, I would definitely go turbo, considering your application and goals for the car, but a good turbo setup is gonna cost you a serious amount of money. The nice thing about a turbo setup is that under normal load (ie, daily driving, raod trips, etc) , the turbo will not put as much undue stress on the engine as a supercharger will.

On the other hand, your system would have to be totally custom built, which could and probably would involve a lot of down time. At this time, to my knowledge only Turbo Tech and CAS offer turbo kits for the LT1, and as far as I know, neither is tailored to the B-Body, and on a largely modified engine, the Turbo Tech kit is useless anyhow. I don't know how the CAS kits do on modified engines, and I'm not sure there are enough around yet to give a good idea of it.

However you could very easily slap on a supercharger.

What is your budget for the engine?

 

I would go with the turbos simply because more power and better mpg. I feel your 9:1 cr is fie with the boost level your planing on using especialy with the intercooler. The higher compresion will increase torque and therfore decrease turbo lag. but if you plan on having a 2 stage boost system i would try to put in some thicker head gaskets to get i down a point or two. That trans should handle that hp ,

 

Not enough info on the cam. I'm not the cam expert that say ... rskrause is, however.....I know it should be significantly different for a turbo vs blower. That will impact what gearing you choose should you go the 6-speed route too. With a turbo, more than likely you'd be better off with a higher gear ratio (lower numerically) since turbos love load. With the blower more than likely a 3.42 or 3.73 is what you should consider via the M6. Turbo, leave the 3.07 in for really high boost or switch to 3.23 or 3.42 for the lower boost. One thing that you montioned that stands out " I want the car to be tame if I drive it gently and a monster if I get on it." ..... IMO that sounds more like a centrifugal supercharger (since they don't make much boot at the low end) than a turbo, because a turbo can scare the $*&(# out of you when it spools up suddenly at part throttle. Either way you will be spending a lot of money (esp turbo) and will have a big grin on your face with that much torque.

 

Neither, what you need is a positive displacement type blower (like the Eaton, Whipple, or Kenne Bell). These types of blowers make full boost from just off idle, just what you need for a heavy street car.

Just IMHO.

Rich Krause