alright, just was looking on summitracing's website since i need to order a new flexplate for the TH350 conversion. anyways, i have two part numbers

TCI-399173 that is $99.99 and is listed for a 4L60E

then there is

TCI-399753 that is $199.99 which is what i come up with for a '99 5.7L engine

what's the $100 difference gonna be for? both are SFI approved and for a one piece rear main seal. i've always seen the $199.99 version and was just checking shipping date/availability. Wouldn't mind saving $100 if it was gonna work just as well.

Chris

EDIT - cheaper one is externally balanced. both are 153 tooth, but the ATI flexplate on the ATI's website for LS1's is listed as a 168 tooth. now there's another question! what tooth count? haha

 

The Ls1 is 168 tooth count, the tooth count is the number of teeth on the outside of the flexplate, it is how the starter turns the motor over. The 99 dollar one is for a Lt1, the 199 one is for a Ls1.

 

ok, guess i just need to call an LS1tech vendor instead of going through summit to make sure i get the right one. thanks for the info!

 

I just called tci direct to get the info. Just installed the flexplate and it is real beefy. It is thicker than stock. It has dual pattern holes for ls1 converter or sbc converter.