Which one of these two flywheels do you recomend. I have a 305 right now but will eventually drop a 350 in. They are both from GMPP and around $20 dollars difference. I don't know the weight of the second one.

14088646 Flywheel
Outside diameter is 12 3/4" for years 1986-up. Crank Flange bolt pattern: 3.00"; clutch dia.: 10.4", 11"; starter ring gear teeth: 153. Lightweight nodular iron flyweel. Weighs approximately 16 pounds. For one-piece crank seal.

just over $200 at GM Parts Direct


14088650 Flywheel
Outside diameter is 12 3/4" for years 1986-up. Crank Flange bolt pattern: 3.00"; clutch dia.: 10.4"; starter ring gear teeth: 153. Standard weight flywheel for one-piece crank seal.

just under $200 at GM Parts Direct

 

The first one is the LB9 flywheel; the 2nd is the L03 one. It weighs around 25 lbs.

 

Could I use the lightweight flywheel on my L03?

 

Yes.

 

Which would you recommend for a 350 in a street/daily driven car?

 

I would not recommend a lightweight flywheel on a street car. My friend put an aluminum one on his LS1 Trans Am and I could not get his car to spin the tires with some cold nitto 555's! It KILLED all his low end power and his car just bogs off the line. It is quick from a roll though, but not worth it. I have an L03 one it is pretty heavy and i turn 6000 RPM no problems and it is a lot of fun on the street.

 

I know to stay away from an aluminum flywheel because they are so light. Not sure how much one weighs, but this is a light weight steel one, which is a factory option at 16lbs. I don't think it would give me too many problems since it was orginally on a 305 HO. I guess what I'm asking is which would be best for a street driven 350 and why?

 

How does a lighter flywheel kill low end torque????

 

No inertia.

 

It doesn't "kill torque". What a light flywheel does, is to not store alot of energy; so whatever energy is stored up in it, gets used up quick as you let out the clutch.

A heavy flywheel is better for a heavy car with a gas mileage gear; that way, when you let the clutch out without revving up the engine first, there's a little energy stored in it to get the car moving. A lighter flywheel is harder to drive because you'll tend to kill the motor doing that; or, you tend to go through clutches faster.

A light flywheel is better for a light car with lots of gear, or a very skillful stick-shift driver.

Personally, I'd prefer the lighter one. Oh wait..... maybe that's because my car (L69, 3.73 gears) already has it.

 

I wouldn't put an aluminum one in much either.

But an aluminum one is quite different from the 16lb L69/LB9 iron wheel.

I would go for the lighter of the two that were posted. That's what I've used in my 86. Matter of fact, I might have a new one for sale in a few months.

-Matthew

 

is it ok to put a 16# flywheel on a 305 tpi with 3.42 rear and aluminum driveshaft? or would that be too light for the whole setup? what weight flywheel would you recomend for my application, im going to be using centerforce DF clutch, and also does anyone know the weight of the stock flywheel?

 

Aboiut 16 lbs

Should be fine

 

 

The stock LB9 one, the one that he asked about, is around 16 lbs.

 

My bad. He posted 16# in the same reply so I thought he knew the weight of that one.

 

so if the stock one is 16# then it would be pointless to buy the lightweight 16# that i have been looking at correct?

 

Correct. It's probably the same exact thing with some marketing thrown in.

-Matthew

 

Both of the flywheels at the top of the page are stock, from GM. One is for the L03 and the lightweight one is for the LB9.

 

use the stock one from your 305 16lbs working fine for me gets both front wheels in the air and 1.65 60 foot times