2.8 flywheel ???

I have an 86 blazer S10, 4X4, standard. This past weekend I replaced the motor with a 2.8 from another 86 blazer, 4x4 S10 AUTOMATIC. I swapped the fly wheel from the old motor to the new. Now I have a very bad vibration from the motor. I changed the harmonic balancer but it made no difference. 1 guy tells me that I have to have an externally balanced flywheel from an 87-89 2.8. I have tried everything else but i really dont want to drop this transfer case and tranny again if I dont have to. (miserable job on the S10). I replaced the the clutch and pressure plate, and the motor mounts were in good shape. Does this sound true to anyone? I dont understand why the blocks would be different. Im using the same flywheel from the original motor and they are both the same year. I did notice that the plug wires are in the proper order however the #1 wire starts at 1:00 vice 7:00 on the cap. Will that make a difference?

Thanks

Rich

Not sure about late models, but did you put a pilot bearing in the back of the crankshaft?

If not it could cause the front shaft on the trans to wobble and vibrate.

Someone else might be able to confirm if this might be the problem or not.

Years ago I converted 2 57 Chevy's from auto to manual and had to put the pilot bearing in.

Jerry

From what I understand all the 2.8L engines are balanced the same. Did it run right in his truck?

Yes I did put a new pilot bearing in. Is the 86 2.8 Internally or externally balanced? 1 guy said that in 88 is when they went to the externally balanced motor, but i havent been able to confirm this. One item I did discover is that the #1 plug wire starts at the 1:00 position instead of the 7:00 position. The order is correct 123456. Would that have any effect even if they are in the correct order? This is a little difficult for me to actually do anything during the week since i am in the service and stationed in CT and this is my sons blazer and he is in ny. I wont be able to actually work on it until i get up there this weekend. But I would like to know whether I have to pull the tranny and change the flywheel or not. If the flywheel is correct or not.
thank you for your help.

Going broke with yung'uns truck,
Rich

I can only really answer 1 question. All 2.8L engines are externaly balanced. Unless my info is wrong. But even if it is your motor wasn't introduced until 85 (smaller journals before then) and they wouldn't likely change anything major that soon

Your right the position of the #1 cylinder on the cap shouldn't make a difference as long as the firing order is right.... which it is.

Check out this web site. It might have some info that could help you
http://users.spec.net/home/emxjc/

I wish that you would have gone on this forum before the job was done, there are better more reliable motors out there that would have bolted right in. Too late now