[akduck]

Resently bought a 68 at a auction, it has a vibration that is connectted to the rpm's. Knowing that they just worked of the trans. I wonder if the incorrect flywheell was used? Can any one tell me what the correct flywheel is for a suffix code pdj 454 block "91 truck"?

 

[blainedoe]

that 454 is externaly balanced. the flywheel should have a big weight cast into it. if they used an internal balanced flywheel say from a 396 you could have that problem. could be other things too.you just need to go thru the process of elimination till you find it good luck.

 

[Everett#2390]

Or they may have gotten the 454 flywheel 'clocked' wrong.

Welcome to the Club!

 

[JUNK YARD DOG]

454 and sb 400 both have a fairly large weight on the flywheels you need to make sure its not a 400 .the 454 flywheel has a cut out for one of the torke converter bolts and the 400 weight is not cut out .very easy mistake to make.

 

[akduck]

Thanks for the replys, I am digging up some awnsers and will post them when I have them.:thumbsup:

 

[akduck]

It has a 4 speed muncie behind the 454, I do have a correct flywheel, found from the casting #'s. I was told that it is imposible to "clock" it wrong because it has a dowl pin that lines up. What other things should I be checking at this point?

 

[Everett#2390]

Does the engine 'hit' on all eight cylinders? Run smooth?
Temperature gun shows what temps at exhaust manifolds for each cylinder?
Vacuum gauge shows a steady reading? What value?
Compression testing shows?
Intake system is?
Run engine without belts to see if it smooths out?

 

[rattec]

If it has a 1 piece re-main seal, you have a gen V or VI block and the flywheel is different than older 454 's (gen IV). Gen VI started in 1996 with the vortech heads. Gen 6 has an aluminum timing cover also. I ran into the same problem with my gen VI block. Also make sure to use the gen v balancer. Another note, gen IV heads don't work on a gen V, but will on a gen VI. Any questions I would be glad to help, I have been down this gen 4,5,6 road and it was a little rocky at times.

 

[akduck]

I have pulled the flywheel and it looks to me that I have a one piece seal. What flywheel is correct for the Gen V or VI block. Any help woiuld be great.

 

[Z15CAM]

Aside form the matter that the 454 requires a specific balanced Harmonic damper and flywheel; per-say, the crank was changed out for an after market and the assembly not balanced: perhaps a piston or rod combo was replaced that has different weights or hopefully a bad universal joint on the drive shaft or badly balanced clutch on your Muncie. NOTE: usually engine balancers will drill the 454 Damper and Flywheel to archive balance apposed to balancing the crank. I personally prefer the balancing on the 454 crank rather then disturbing Mfgr's specs of the damper or flywheel because if you change out Pistons and Rods they are within a + or - 2 grams.

 

[pdq67]

Clocked wrong, EASY, just don't line it up to the dowel hole, (pin if it has one)!

pdq67