Non-standard 440-727 flexplate-converter bolts?

[FastbackJon]

Noticed one of the four bolts attaching the 440's flex plate to the 727's torque converter is missing on the '68 R/T Charger.

Bought some standard 440 attaching bolts and noticed the head size of the bolts in the package is a lot smaller compared to the three still on the car which take a 3/4" socket.

Any ideas on where to find a matching bolt?

[Tilar]

Not sure where to tell you to get one but I would stick a magnet up in there to make sure the old bolt isn't stuck up inside there somewhere waiting to get caught on that starter ring gear.

[BSB67]

Are the converter bolt thread size different too?  There are two sizes used, 5/16" and 7/16". 

Are the threads any good?

[John_Kunkel]

If the current bolts in the car take a 3/4" socket, you have the 7/16" thread (Hemi) bolts. The standard bolts are 5/16" thread.

Use red Loctite when installing the converter bolts.

[fy469rtse]

I agree with John , but on closer inspection , there's a deep gouge to flex plate ,
That was caused by that missing bolt,
Missed matched sizing , converter bolts need to the same size as flex plate ? Stock size on converter , aftermarket larger ones to flex plate, bolts are high tensile , reduced thickness to heads for clearance
Lock tight a must , and I would keep this in the back of your mind if auto ever has to come out , at least match flex plate to bolt size, importantance level high on my list
You got lucky with only one coming out,
Re lock tight to the others, I'm betting there not that tight

[FastbackJon]

Thanks all, yes I bought the 440 (5/16") bolts when I saw the one missing and with another one rotated around it looks like I need to go back and get the 426 (7/16") bolts with the 3/4" socket head. Yes, hopefully the threads are good and a new bolt will go back in. I can check for pieces of the missing one too.

No idea how long it's been missing. This car was built by someone else in the 1980's, sold to us in the early 90's and not driven hardly at all. I've been under the car many times but didn't notice the missing bolt until it was up on a friend's lift and it just happened to be rotated to where it was obvious.

Red loctite is smart too. Thank you!!

[fy469rtse]

just periodically check this , if it were my car would be on the to do list