Most V6's use a 153 tooth, 10-1/2" flywheel & clutch assembly. The 153-tooth flywheels may be drilled for 8, 9, 9-1/2 or 10-1/2" clutches, depending on what engine they were originally used on.
While it is possible to have a flywheel redrilled to accept a larger clutch, this must be done with extreme accuracy or the weight of the pressure plate will cause imbalance. To be done properly, a vertical milling machine and rotary table attachment with suitable dial indicator, drills and tap are required.
All modern Chevy V6 and V8 engines continue to use the same block pattern as introduced in 1955. Chevy V6 flywheels are typically 10-1/2", but will not interchange with the V8 versions due to balance.
So I need the 153 tooth, 10-1/2" flywheel...where do I get one cheap?
On my 4.3 swap I just bought an engine from a manual C1500 half ton truck...
When I checked the flywheel out compared to a 350 flywheel I had around the shop the 4.3 one actually was heavier.... whether this was for all 4.3's or not...?
For my swap the disc was already the 10.5"
I used a lakewood bellhousing for a camaro application (hydraulic clutch ) and have had no problems.
This is of interest to me as I'm doing a similar swap, 4.3 and SM465, I was under the impression as long as you are using an '88 or newer flywheel for the 90deg CSB motors you were okay. Therefore you could use a 12" flywheel on the 4.3. Who has the answers?
A forum community dedicated to custom off-road vehicle owners and enthusiasts. Come join the discussion about trail reports, builds, performance, modifications, classifieds, troubleshooting, fabrication, drivetrain, and more!