AnotherWs6

iTrader: (17)

Like the title says..... I'm ready to change the transmission in my 2000 5.3 Silverado. I purchased a Performabuilt level 2 trans and a 3,400 RPM Circle D converter. I've been told that the factory flex plates are prone to cracking and if they are cracked they should be changed.

Thing is, I don't know which one to get and the price range is like $30 - $300. I go on Summit and there are ones listed for my vehicle that are externally balanced AND ones that are internally balanced. So which one is mine? I'm assuming they are referring to the motor.

Does the weight of the plate have any effect on performance like a flywheel does?

How strong does it need to be? I don't race this thing and only beat on it occasionally. It's an older truck with bigger tires, is swapping it with a fresh stock one a good idea? Aftermarket cheapy OK?

Is there a go to one? I'd prefer to not even replace it after all of the money I've already spent, but if I'm taking the tranny out I'd like to be prepared with a new one in case mine looks rough.

ATK Engines

iTrader: (1)

Internally balanced SFI flex plate is the way to go. Stick with a name brand and you're fine (B&M, TCI, Etc). SFI is a much stronger setup and most tracks will require to you use one, although they dont always check.

https://www.summitracing.com/parts/b...make/chevrolet

kinglt-1

iTrader: (26)

If its not cracked and in good shape I would run it unless its going to be drag raced all the time.

AnotherWs6

iTrader: (17)

Thing is is that I don't know if it's cracked. I don't want to pull the trans and find out that it is and not have a new one.

Not sure that that B&M one is SFI, which doesn't matter to me except that if it is I imagine it's probably decent quality. What about this guy? Look right and OK?

https://www.summitracing.com/parts/s...5sfi/overview/

ATK Engines

iTrader: (1)

The B&M is SFI, is states it and shows the sticker. I would stick to this one. For $90 its cheap insurance and something you can use in the future if you go for more power.

AnotherWs6

iTrader: (17)

This is stated in the description so it's a little odd.... Some units are SFI-approved and are NHRA/IHRA-legal for all classes

I don't see why some would be and some not. Amazon's description agrees with you though, I tossed it in my cart for now.

Do I need new bolts or are the factory ones OK?

DANOZ28

iTrader: (1)

fyi should be posted in auto trans ; an sfi flexplate generally is twice as thick as my 99 stock plate. for peace of mind i added an $85 new sfi plate when changing my stall. if you had really big hp circle d makes a heavy heavy duty one. some years got slightly stronger stock plates.

AnotherWs6

iTrader: (17)

Thanks dano. Which one did you end up going with?

Circle D's flex plate is super overkill for my mostly stock truck, and it's loot. I think they may have a cheaper version. Not sure but when I bought my converter they said they were out of stock on what they would recomend. I can't imagine it's the one on their website, they knew the application and I think it obviously doesn't need anything crazy.

But they are the ones who tipped me off to cracked plates. And now I've seen some things pop up on the forum here and there so I'd rather be safe than sorry.

5.7stroker

iTrader: (36)

TCI makes one that has pretty much never cracked, but it's pricey at $250.

399753 is the part number.

I recommend putting a new rear main seal on while it's apart as well.

I'll probably go with the B&M one.

Are longer bolts needed with the B&M like they are for the TCI due to the TCI being thicker? The overall bolt length will depend on the converter used, but if you already have a converter and stock flexplate and are going to the B&M, are new/longer bolts needed?

AnotherWs6

iTrader: (17)

I am going to go with the B&M. Circle D includes converter bolts, I am assuming that those will work. Unsure of the flexplate bolts.

5.7stroker

iTrader: (36)

For flexplate bolts I'm going to run the ARP 2442901. The B&M doesn't come with bolts. With the converter bolts you may need to go with 18mm. That's the size used with a Yank converter and B&M plate. Each converter is different so depending on which one you have and which flexplate you are running, will determine the converter bolt length.

AnotherWs6

iTrader: (17)

Right, and I was checking out those same ARP bolts. Do you think it matters if the are changed or not? I mean the factory ones have been there forever and are fine, and I dont see this being a very highly stressed kind of thing.

Again, Circle D Supplies converter bolts so hopefully that isn't an issue. I couldn't imagine the B&M plate being so different that different bolts are needed.

Anybody have any experience with this flywheel/flex holder?

http://www.ebay.com/itm/LS1-LS2-LS3-...066556&vxp=mtr

5.7stroker

iTrader: (36)

I'm not sure if they are needed or not, but for $28.08 shipped from Amazon, I figured why not just for added piece of mind. Dropping the trans is a longer job than I would like it to be, so I'm going to be changing the rms and cover gaskets. Fel-pro BS40640 is the gasket kit to go with.

98CayenneT/A

I have had my transmission and converter out many many times and have always used blue loc tight with zero issues ( figured i would toss that in there since I saw your other thread also) torqued down to 45 ft/lbs.

As far as flex plate to crank, I reused my stock bolts.
Converter to flex plate are also my stock bolts with B&M sfi flex plate.

That flex plate holder is not necessary but absolutely would help.

AnotherWs6

iTrader: (17)

Yup, already got that fel-pro in my cart. Hoping it will help cut down on oil leakage. I'm assuming it leaks a little, enough that over the years the whole bottom of my motor and tranny are covered with oil.

I wasn't planning on changing the anything besdies the converter and trans. Now I'm 20 bucks for RMS, 100 bucks for Flexplate, 30 bucks for bolts....S never ends.

I was thinking about this little guy too. Brian at Circle D mentioned holders on ebay that use your starter mounting holes and hold the plate in place. I dunno if this guy would do a sufficient job at holding and then be useful for turning down the road.

https://www.amazon.com/gp/product/B0...A1UMBRA5ZTBCX8

AnotherWs6

iTrader: (17)

Thanks 98. So that's the same flexplate I am going to buy so maybe I just save my $30 on bolts. Not trying to be super cheap, but if there is no benefit....eh. This isn't a performance vehicle, it's a mostly stock truck. And as far as the quality of the GM bolts goes ---- the bolts I used on my rear gear/diff were new fng Chinese ones that came with an install kit. After they walked out and sheared off I went and found my factory bolts with 300K miles on them. Said screw it and impact gunned em on and Bob's your uncle, no problems since. (With loc-tite again)