i just got a "3.4 flywheel" today and when i got my old 88 one out i noticed that the 3.4 had a big weight on it. From what i understand is that the 87 and later 2.8's have a externally balanced flywheel and the 88 and newer are internally balanced. The guy at the place i got it said that 88 and up are interchangable so mabye i didn't even need a 3.4 flywheel. My question is, if i am right and they gave me the wrong flywheel and then they would owe me a 3.4 one? Or is it the right one and i just got my facts mixed up?

i gotta go back there tomorrow and i don't wanna seem like some retard without knowing for sure that i got the wrong one.

 

Not sure but if you can go from my experience I used the flywheel from my 87 2.8 on my 3.4 (b/c it was resurfaced) and when it gets up around 3k- 4500k it vibrates really bad. So I took the flywheel from the 3.4 and got it resurfaced and put it back on and runs like a champ. Good power throughout all gears. Just what I experienced so hope it helps.

 

that's exactly what mine was doing only really bad, thanks for the input tho i appreciate it.
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u wouldn't happen to remeber if ur old flywheel had a weight on it the size of a brake pad alomst it's pretty big cause that's what this one has.

 

There should be no additional weight or recess on the flywheel you need. It should be uniform all the way around.

What you have is an early external balance flywheel.

 

that's exactly what i thought. It turns out that the casting number wasn't right on it either when i brought it in. Now imagine if i put everything back in and never noiticed and had to do it all again i would be one pissed off camper. Thanks for the help guys.

 

I had a similar experience with my S10 pickup. Its an 87 with EB flexplate. Just to make sure, I put an IB flywheel on it. Shook really bad almost right off idle. IB flexplates have holes all the way around, EB have holes on half and a weight.

 

i finally got the right flywheel last night and i installed it all and it runs awesome even out of time it runs way smoother than it was b4. I noticed my old flywheel on one side had like 15 holes in it and the other sides only had like 4 so i wounder if someone used this for a older engine and got it internally balanced to a 86 or something cause it was a 88 and it didn't work on my 3.4 swap and i have no idea how the old engine ran cause i got it seized. The old engine (as i found out when taking the oil pan off) spun a rod, threw a bearing and actually snapped the connecting rod. The way this guy works is he gets like one engine that's got a oiling problem and one engine that has a crack in the block and makes one out of it so he might have had this flywheel with older heads that the oil gallerys weren't matched up, that would cause a major oil problem along with this crazy shake. He actually drove it for 20 miles (or however far Kingsville is from here) and it went on him.