When i put my golen 383 together about 5 years ago I bought a flexplate from them. It looked like they had just cut the balance weight off a new stocker. I didn't mind, at the time i didn't have the skills or tools to do it myself and it was cheap enough for a new one that i knew was going to work. I was never advised to put a keyed hub on and never had a problem.

 

Sorry, Rich. I am going to disagree with you on this one...

You do NOT need a keyed damper on an LT1.
The woodruff key was not intended to keep the damper from spinning. It was originally used to align the old school dampers that need a timing reference mark. Since LT1s do not use timing marks, it is not needed. It was also used on the 400SBC to make sure that the balancer was in the right position. The 400 was externally balanced at both ends and had a special balancer with a counterweight instead of a traditional damper.

It is the interference fit is what keeps a damper from spinning. Now, with supercharged engines, this does not apply. They need a keyway to prevent to load on the balancer from spinning it. A single keyway is not usually sufficient so they use a double key set up.

I speak from experience here. I had an old BBC that I replaced the crank in and the machine shop took off a little too much off the snout when they polished it. The balancer went on a little too easy. After a few (dozen) hard shifts, the balancer ripped out the keyway and gouged the end of the crank and almost spun off.

Again, Interference fit is the key.

 

I just see the key as a little "insurance" with no downside.

Rich

 

That I can agree with.

 

I had a new flex plate balanced when the machine shop was balancing the crank. They didn't take much off the flex plate but I am assured that it's netural balance. I also replaced the dampner at the same time. I personally would not use the originals with 150,000 miles on a new motor.

 

How much did balancing a flexplate cost at your machine ship? New ones are oly like $100 from Golen. Thanks for the input so far. Im learning alot...

 

Being I was getting the crank balanced they charged me like $ 10.00 extra along with repolishing the crank and giving me a bunch of assembly lube packets. If I remember correctly the flex plate cost around $55.00 new.

 

It will probably be worth the money to buy a new on Im thinking... Hays sell a good one for like 85 bucks. Its stronger and you can get them balanced however you wish.

 

Chad sells a keyed hub you can bolt your stock damper to.
I think it's about 100.00.