Harmonic Balancers:What size came on what?

[special-K]

I know we have alot of small block I.D. questions here and we tell where the numbers are or look up the numbers and figure it out,usually.But,just to look under the hood and take notice of the balancer can at least give and idea of what motor it is by that.There could be the wrong one,some motors share the same,and all that.It`s not the Godspell,but it`s a good point of reference if you`re looking a vehicle over to buy(or whatever)and don`t have the numbers info or can`t clean that spot on whoever`s motor.
I`ve bought trucks that were said to have motors of this size or that,only to find it was not.I`m not absolutely sure of the variations in harmonic balancers and figure between us all we could get the lowdown and set it straight.I have a truck that was s`posed to have a 400SBC and another that was s`posed to be a 327 and neither are.The 400 wannabee I bought and had shipped,so I never got to check it out and took their word.The 327 wannabee is my`71 wrecker and I knew that was no 327 by the lack of crankcase vent tube and other external differences.I wanted a 327 for my`67 project,but wanted a bigger motor for the wrecker.So,it was no big deal that it was a 350.
When listing what you know give the approximateeyeball)thickness,such as a 307 is about 3/4"/the 350 is about 1 1/2".If two displacements share a balancer,list it that way.Give any other characyeristics that could help,too.I want this to be a good reference for all to make note.Well,not for know-it-alls.This is a waste of time for you guys.

[special-K]

No one knows?

[carl609]

I know that a 400 balancer is big, and has a cut out about half way around it on the inner side of the outside diameter, I hope that makes sense. I will take a picture of a real 400 balancer this weekend. most of the 327s I have seen have a small balancer, but so do 305s. And most people that deal with a pile of parts like most of us have, will just grab what they have if it is good. Only true way of knowing what engine you have is by the casting numbers. I believe the only balancer that is crucial is the 400, as it is extenally balanced and the rest are balanced internally. Also, a 400 flex plate will have weights on it.

[Longhorn Man]

400's are dead easy to ID... and they are far and few between.

[mrein3]

Originally Posted by Longhorn Man

400's are dead easy to ID... and they are far and few between.

Yes. They look just like the one on the front of my 383. Note the "cut out area" as carl609 points out in the LHS and RHS view.

[Long Roof]

All the 350 4bolt main blocks I have seen stock had a 8" balancer. I agree that the 400 is easy to spot.

[special-K]

This is good info,for when numbers aren`t handy.That`s all I wanted people to see.I have never been sure that what I`ve heard was accurate.I have the cut-outs in the balancer on the Highlander which was said to have a 400 and I figured the seller was going by the "400" emblems since the body came from a 2wd 402 truck.My wrecker was saidto have a 327,but it has a later intake and no vent tube.It does have a small balancer,though,and I was afraid it may have a 307 swapped-in.It`s a`71 or`72 truck with a c/10 cab`n`clip from`71.So,who knows what it is.I`m going to run the numbers on all my stuff.The only motor I know for sure is a 350,at this point,is the one in my GMC.That`s because it was in my CheyenneSuper and I rebuilt it.
I`ve never been hung-up on numbers and such,just results.But,I started this thread when I realized I really didn`t know for sure what had what.It`s funny,all I mess with on these trucks and I can`t swear what motors I have.