Hi All,

Finished my restore three years ago and been driving without issues. The engine is a 78 360 75k on it. I replaced all pumps and seals but left the piston, and crank assembly alone. I had the heads redone and replaced timing chain, etc.
The 904 is stock, I adjusted the bands and replaced the filter and drained everything including the torque converter.

I installed a B and M flex plate and verified the part number before posting this. Also I have dropped the transmission to check the plate and it looks fine, its still mounted, but I can see most of it.

I think I have had now for a while some piston slap that would disappear after warm up, so now I'm not sure if this sound is related.

So take a listen, hopefully I have copied this URL correctly.

If you can see in the video, the noise is most noticeable inside at the trans hump. I can also feel the knock on the passenger side motor mount.

https://youtu.be/LkGI0o7617w

hard to tell, sounds to me like its touching the body somewhere, maybe a socket or spanner fell down and got wedged against body/trans case, just a thought.

when my brother was growing up, i had a bunch of tools come up missing. usually, some were found when "strange noises" came up for me to diagnose. funny how that works. one time, i found a 5/8" open/box wrench still attached to the upper starter bolt on my sister's 74 satelite [318]. come to find out it was left there when my bro changed the battery cable on the starter, stuffed it back in, then couldn't get the wrench off the bolt after tightening it. ah well, just leave it in there ........ no noises, so i didn't find that one until a couple years later when she had starter problems.

Exhaust hitting the transmission cross member and did you use blue loctite on the converter bolts.

bearing (I think there are vids/info on how to somewhat accurately tell if it is a rod or a main). less likely piston/pin issue. Just me, the prognosis dont sound good (needs to be opened up).

Check to see if one or more flex plate bolts has come loose.

If one or more back out, the bolt heads rub on the webbing at the back of the engine.

^^^ agreed, definitely an easier non invasive check.

In his first post he said he dropped the plate and can see most of the flex plate.

I'd cut the oil filter open and I bet you find metal. If so time for a engine rebuild.

How is the transmission mount?