are 86 and newer the same as the pre 86 flexplates (stock 305-350)? i've seen different and same pn#'s from different manufacturers.
TIA

 

No. The bolt pattern is different where they bolt to the crank.

 

they are balanced differently also.

 

ok that explains it. i wasnt sure if it was because of the rear main or not. so then the pn#' s that will fit both are probably dual patteren drilled. thanks i'm used to dealing with the pre 86 stuff.

 

305-350's are internally balanced, did they start doing something different in 86?

 

the newer style flywheels have a "bat" shaped weight on them and are not compatable with earlier cranks.

The number of teeth can be different too.

 

with the exception of 400's, 262 through 350 were internally balanced engines up until 1986. in 1986 when the one piece rear main seal was installed, the flexplate/flywheel end became external balanced and the harmonic balancer stayed internally balanced.