speedway balance plate for 383 or 400 sbc???

[100mphwheelspinner]

I have a new 350 flywheel and I am thinking of going this route. Speedway sells these balancing plates for $12.95. I am getting ready to put a new 383 in my coupe in place of the 350. Speedways ad reads. "When running a 383 or 400 S/B Chevy with a 153 tooth flexplate or flywheel, you need to have a balancing plate. These fit between the crankshaft and flexplate and correctly balance the engine without resorting to a big heavy flywheel." does anyone know anything about these???

[Tudor]

383's use a 400 crank and 400 cranks are externally balanced so - you have to use a 400 flywheel and 400 harmonic balancer. The flywheels just have a weight welded on them where as the 350 flyweel doesn't. I am not sure about "balancing plates" and what fly wheel they require.

[AnimalAin]

The plate is assymetric to give the proper imbalance for the 383/400. Just like adding the imbalance weight to the flexplate/flywheel. Certainly cheaper than a new flywheel, although the accuracy of the imbalance may not be as exact. If your motor isn't precision balanced, it is certainly close enough.

[Bugman]

What happens when you run a 400 with the stock damper, but no balance plate with the flexplate?

-Bugman Jeff

[Curly]

[ QUOTE ]
What happens when you run a 400 with the stock damper, but no balance plate with the flexplate?

-Bugman Jeff

[/ QUOTE ]

Stock style crank, stock style dampner, stock style flexplate = no problems (all externally balanced).

Change anyone of those components with a part from an internally balanced SBC (anything other than a 400) and you will get a reciprocating mass that will vibrate to the point that stuff will just come apart inside that motor. More revs the faster it will come apart. Run it to 8 grand and you'll make SBC mean small BOMB chevy. Remember the old Batman series? KABOOM, POW and all other sorts of weird sounds http://www.jalopyjournal.com/ubbthreads/images/graemlins/crazy.gif http://www.jalopyjournal.com/ubbthreads/images/graemlins/blush.gif http://www.jalopyjournal.com/ubbthreads/images/graemlins/frown.gif

[Phil1934]

I used one and the startere would keep cranking as it moved the flywheel back 1/8". I tried everything before I finally bought a Hayes 153 tooth ext. balanced flywheel.

[Rocky]

I also used one on a 168 tooth stick flywheel...worked like a champ for me and only cost me 12 bucks. Kept the stock 400 dampener on the front and used a 350 manual flywheel on the back.....buzzed the 406 to 6 grand any number of times with no apparentno problems here..

[Bugman]

[ QUOTE ]
KABOOM, POW and all other sorts of weird sounds

[/ QUOTE ]

That's kinda what I figured would happen. It's be fun to watch, but sounds kinda pricey http://www.jalopyjournal.com/ubbthreads/images/graemlins/smirk.gif