454 off idle vibration

[johnathan]

After the SB to 454 swap everything checked out great.Runs great all except for a significant vibration off idle to about 1100 then it smooths out.All cylinders are firing.I had to swap flywheels to mount to the 700r4 converter.Would this matter?Any thoughts,suggestions?

 

[mtnman]

older 454s use a counterbalanced flexplate - is the one you used from an older 454 - not sure if the late models are counterbalanced or not

 

[johnathan]

The one that was on the 454 was counter-balanced,it had a huge weight on it.I used the wheel from the 350 in order to be able to bolt to the converter on the 700r4.I don't think the flywheel had any wieghts on it.The older flywheel would not bolt up to the 700r4,the bolt holes were about a 1/4in. off. Could I drill the holes out larger or is that a bad idea.The torque converter centers itself inside the crank, right so the bolt holes would.nt be needed to center it.

 

[4X4HIGH]

You must use the 454 flexplate. The 454 is external balanced and is all by itself and not interchangable with any other flexplate.

Buy the correct flexplate. There is a flexplate for a 454 that has dual bolt patterns for the convertor. Don't try to enlarge the holes in the current 454 flexplate. Flexplates are only about $35.00.

 

[mtnman]

agreed!!