I have 2 different 1979 460 engines from trucks. One has a round spacer sort of like a piece of pipe, the other has a counterweight on it (#D9TE-6359-AA). I'm not sure which one is correct or how to tell which one to use as I don't trust the fact that just because it was there that it belongs there. I thought these were internally balanced engines so I'm thinking the counterweight one might not belong? Any ideas? Thanks

 

If those engines are in fact 79's, they should be externally balanced. The only way to be sure is to look at the casting #s on the crank.

Anyways, the spacer without the counter-weight is for internally balanced engines. The big counter-weight spacer belongs on externally balanced engines.

 

Look at your flywheel if it has a counter weight formed into it put the front weight one on it. If it has a flex plate and there is a counter weight welded to it put it on. All 385's were internaly balanced. Sure you don't have a 428? as they had these.Where as the 390 had a spacer.

 

Umm, no they weren't. The 460 became externally balanced in 79'.

 

Ditto.

 

I stand corrected. And some did have a external front counter weight, just like 428 scj's.

 

I am having my 460 rebuilt and just got it back from the engine balancer. He said the front counterweight does belong and the flexplate also has a weight welded to it. (I ordered a new flexplate and there was only one part #). This is a DT9 block. Just wanted to let you guys know the end results.

 

Where is the casting number on the crankshaft located? I have a bad vibration in my 460 at idle and at driving speeds that I have not yet pinpointed. The rebuilder said it was a 1971 block and crank, but I would like to be sure. It has no external weights on either harmonic damper spacer or flexplate. The only other possibility I can think of is that the pilot bushing is the wrong one for the torque converter. When I take out the transmission, I sure would like to confirm that my crank is an internal balanced one. Will an internal balance (no weights) flexplate fit on an external balanced crankshaft? Maybe that will be all I need. Thank you for your advice. Great forum!

 

The casting # is stamped on the front throw of the crank. You have to drop the pan to get to it. Mine is 3YA. I think a 71 is supposed to have these external weights which will fit on your engine but maybe some other member or a machine shop can confirm this.

 

for what it's worth, i just tore down my 460 out of a 71 linclon car. it's internally balanced.