I sent a pair of stick flywheels out to have them cleaned and resurfaced, told the machinist i needed them to marked and kept in order..and i got them back in bags with no markings etc

is there a visual que for differences? i have clean ready to use 67 and earlier flywheel and 68 and later but dont know which is which...anyone able to guide me to which is which...theres no marks etc and want to use the 68 and later and sell the 67

i know i should have done it different but it took him a month to return them, and i knew that would happen but i am confused on which is which

is the bolt pattern to the crank different..is it a balance thing? thanks in advance

 

The bolt pattern is different early vs. later.

If you have a known crank laying around, you'll be able to figure it out pretty quickly.

Don't know if weight/balance is an issue. Someone else will have to answer that.

 

Are you going to use them or sell them? The bolt pattern is the difference. Do you have a flex plate from either one to compare too?

 

easy as pie
get yourself a measuring stick
calipers, toothpick, pc of paper, etc.

Measure from one hole to the next. The exact number does not matter as long as you measure the same way each time. Left side to left, close side to close, far to far, just do it the same way each pair. You will find that the spacing will be one of three values. Let's call them S M & L for Short Medium and Long.

pre-68 there was ONE hole offset one direction, making for 4 alike spacings [Medium] and one Long and one Short. Therefore if you mark your spacings it will look like this
MMMMSL or MMMMLS if you look at the other side
or obviously MSLMMM and other variants are the same, depending on where you start and what direction you go.

post-67, there are TWO holes offset [the other direction] and so the pattern will go
MMSLSL or the like. Only two M's here is the obvious difference. Twice as many L's and S's as the older crank pattern.

Sometimes you can see the ghost of the crank notch on the flywheel mating surface. With rare exception*, the "L" notch was a forged crank, pre-68; the C notch would be a cast crank as used 1968-up.


*There were a few 350's with cast cranks with an L notch, and of course the 455 forging with a J notch. Very rare to see either of these.

 

i dont have a flex plate to check...

i am going to selll the early one and use the other

i will try the measurin' stick

 

did you ever get the flywheels figured out?

Gene

 

yes,,i did,,i kew what they where in the beginning..but the machinist didnt mark them for me, once they where clean the stuff i had on them where gone..i didnt think about stamping them...

anyway..i am using the later on my 68..the other i will prob sell..i dont plan on buying another project..its from a 67 400 442..prob is im so busy with work i dont have time to deal with it right now

 

OK..just so everyone knows...i measured both, i recently picked up a 350 man trans motor, so its a known flywheel..and they measured exactly like Octania said..

i couldnt see the ghost mark, because the machine shop thermal cleaned it..all traces gone...

i measured the 350 because i knew what it was, i just took it off the motor...and then the early 400 and they exactly matched everything he said...

the early matched-mmmmsl

just like he said it would...

i wish i could thank him..i wonder if he knows/knew how many people he has and will help...