Fly Wheel Loose

I just put a rebuilt Long Block in my 1991 S-10 4.3L. I have 2400 miles on the new motor and I am hearing a knocking sound. I hear the sound in park and neutral. When I put the car in drive it goes away. I thought a rod went out in the motor. Does any body know how hard to check to see if the fly is loose. I had some one say sounds like the fly wheel is loose.

Is it easy to get to?

Thanks

You might check the torque converter bolts first.
If the motor oil is too thick, the lifters will peck.

Well I know it is not the rods, I got the ftans mission dust cover and spun the fly wheel by hand and I hear the knowking in either the Torque converter or the trans mission, any suggestions how to check?

Thanks

This thread is in the Blazer section, thats why I opened a new one.

If the bottom 2 of each side of the transmission bolts are loose and there is a 1/8 to 1/4 inch gap will the transmission or flywheel make a knocking sound. Please do not close this post. The other post is under Blazers, this is a 91 s-10, 4.3 l, v6 new rebuild long block installed.

Thanks

I don't know, can you tighten everything up and see if it quit knocking?