Get another set of eyes to look around the car. Look all around the shop, under tables, benches, took boxes, etc. Those suckers can roll. Look on any crevice on the car (I know things like to fall onto the cross member, look there really well.)

IF the nut is in the oil pan, I don't see what damage it could cause. That's only if it's in the oil pan and not setting between moving parts. It's big enough that I couldn't move once it was settled in the pan.

I'd say a good move would be to get a super strong rare earth magnet and stick it on the bottom of the pan. If it's in there, it won't move.

 

i think 69 may be getting at something i didnt think about, if it could bounce up under the intake then there are a host of nasty places it could be. there are a couple oil drain holes in there.

 

Its not like the nut shot into the distributor cap at 1000 mph.....it just fell in that direction. I guess this is the big question....can a 1/2 (od) -(small) nut fall from the dist hole to the oil pan? -Funny story, when I bought my first 350the..... as I installed it from engine stand to hoist a giant 3/4 washer fell in the exact same spot......luckily the engine was out of the car and I was pulling off the oil pan anyways.....there it was in the bottom of the pan.....but that was a big ole washer, not likely to get stuck n any small spots, but it begs me to question how it fell straight thru....

 

What I'm saying is, with the intake manifold on, can you see into the oil valley through the distributor hole? Some blocks are open and some have a wall between the valley and distributor shaft. If it's open, my thought was could the nut have gone down the hole, and go ting...ting...clunk into the lifter valley? But, not only would it be a big fluke for the nut to bounce into the lifter valley, it would be even flukier for it to find a valley hole to drop into. Given the choices, I doubt that's where it went.

 

It is open..........but I pulled the intake last night and its not there. I really think Im gonna have to pull the engine again. Im just trying to come to terms with it. Now, MARK MY WORDS...Ill get the engine pulled, Ill yank the oil pan and there will be no nut in the pan! Two years from now the nut will reappear from the 4th dimension on my garage floor.

 

Dude, Jr. makes a good point, damn DAMN sure that it's not on the floor or stuck inside the suspension or something like that b4 you go pulling the motor.

 

Try one of these, it should find all the loose stuff in the garage.
http://aussiemagnets.com.au/product/...l-Nico%29.html

Seriously, I symphatize with you, as it would be a shame to ruin a good engine because a piece of metal is flying around inside. Small parts have a habit to fall and never hit the ground, always landing in places that can't be reached.

 

I spent 2 hours going over the car and couldnt find anything. I then used compressed air and shot into every nook and cranny and then searched the floor....nothing. Its supposed to be 15 degrees this weekend when I pull this engine. If and when I find this nut, Im going to frame it in my shop as the most expensive nut ever made....

 

dang i thought u were going to tell us u found it. i bet u plug that hole with paper towel next time. like u said its going to be somewhere other than in the motor if u pull the motor, and for me it would be in the motor if i didnt. we feel your pain. so u should only have to pull the cam and the oil pan to look right.

 

theres a lot of reasons why duct tape and masking tape is made-one of the uses is to cover holes you dont want stuff to fall into. i hope you have learned a lot from this experience.

btw, is there oil in the engine yet? if not, have you tried hitting the oil pan with a hammer and listen for a bounce? and there are a lot of hiding places too, including the k-member. but it wont hurt (badly) to pull the engine out and look for it