Which would you ues, 153T or 168T manual flywheel? I am currently building a 421cid small block and can use either size. I have a TKO tranns with Lakewood bell so either one will fit and I believe I have clearance with my Edelbrock headers. I know the larger unit is a bit heavier and has pro's and con's. 168T Heavier= slower revving but would probably idle smoother and can accept the larger clutch. 153T Lighter= quicker revving but uses the smaller clutch. However, I KNOW the 153 will fit with no issues since this is the size that came out.

I have to purchase a new FW now anyway so about the only difference is the cost of a starter. The larger FW costs a little less as does the clutch so that offsets the starter cost somewhat. It really comes down to does the extra weight and size of the clutch with a 168T FW gain any advantages?

 

I'm just gonna give you the easy answer. One fits, one doesn't, no magic here. I found out the hard way several years ago. You want the 153 tooth flywheel. If you want the 168, you'll be wasting so much time trying to make it work. It simply won't because its too big.

 

Thanks for your input and advice. I have decided to go with the 153T. However, I do have a Lakewood bellhousing so the 168 is an option for me. I believe the larger clutch isn't worth the inertia penalty so that's why I went with the 153T.

 

My 168 tooth SFI flywheel is lighter than a stock 153 tooth.

Which actually can be a problem on a street car.

-- Joe

 

Will My Torque converter in my 87 bolt up to 168 tooth flex plate?

 

Good question. Two bolt patterns were used on the automatics, and I know some converters have both some don't.

-- Joe

 

Yeah Joe that can be true. If 2 flywheels of the same weight but different diameters the larger one would have a higher moment of inertia. That is what I meant by penalty.

But your second point brings up a core part of my question which is at what flywheel weight does drivability suffer? Let's put diameters aside for now. I have used a 17lb flywheel and it drove great. Idle could have been a little better but take of was ok. Now I'm leaning toward a 26lb flywheel with my current build. 421cid mild performance (well if 500HP is mild- not all out) and the only reason I am going with the heavier FW is for idle quality. Other than that the 18lb looks good too.