I am having a bit of trouble coming up with stock specs for LS1 flexplates. I purchased a dual pattern 14" weighted flexplate from auto zone (pioneer fra-159). This one seems to be the correct type, but the bolts do not line up with my yank 2800.

I returned the fra-159 and got the fra-160, which is a 12" diameter small bolt pattern, weighted flexplate. And behold, the bolt holes do not seem to line up very well on this one either.

I have what I believe to be a late model (317 heads) LQ9, with a late model 4L60E behind it. I do not see a crank spacer on the crank, and the flexplate currently on the car is a stock early model LQ9 flexplate with a 4L60E converter behind it.

This of course caused all kinds of binding and rubbing, leading to the destruction of my last converter.

What is the correct flexplate part number from GM for this combination. Some places say weighted, others say unweighted, some say 12" diameter plate, and others say 14" diameter...

 

Looks like it is a 12563136, or a FRA-471 by autozone's website? No weight, 168 tooth, 3 hole, 14"? Sorry about the newb questions, unfortunately this is due to a swap into a 3rd gen that went terribly wrong...
FRA-471

 

For future reference LS based engines do not use different diameter flexplates. I've noticed a lot of places haven't caught up yet and will still give you a small block part.

From what I just looked up it looks like you might have the right one now.
12563136 heres a link
And the bottom of this page.

 

Thank you for the info man, autozone part number for that flexplate is FRA-471 from pioneer automotive. Got one ordered up, so hopefully i can get the firebird back together.

Thanks again!

 

Yeah I can confirm that Auto Zone will still offer you the Pioneer FRA-159 for any 98-02 LS1 Fbody and it will NOT fit the crank.

 

The flexplate FRA-471 did end up working just fine, and is the proper plate needed for the LS1 cars with a 4L60E.