Does anyone know for sure the thread size, pitch and length for the bolts that secure the transmission to the engine adapter?

1991 6BT 5.9
A-727 transmission.

Thanks Jim

 

3/8's coarse thread around 1.5" if the memory is working right this morning.

 

I can "partially help" you. I used ZINC PLATED Flange-Head Medium-Strength Steel—Grade 5 bolts that I bought from http://www.mcmaster.com/#hex-head-fl...screws/=l4qvu5 I'm 99% sure they were 3/8-16 UNC. Mine were used with a 5 speed but Your length may differ. I also used Permatex Blue silicone sealer on the threads to eliminate the electrolysis when the threads are exposed to moist air. I've seen quite a few adapters destroyed by using an unplated plain steel bolt. IIRC, Dodge used a flanged head plated bolt in the original application.

 

Jim, 4 from the trans side towards engine are listed as 3/8-16NC X 1-1/2" The 2 from the engine side going back into the case are 7/16-14NC X 2"

HTH

 

Is the adapter plate SAE or Metric?
There was a 3/8-16 bolt there but it is loose in the threads.

Looking for the passenger side where the downpipe support is connected to the bellhousing, the bolt goes back to front.

Geez only 3/8 seems awfully small I am used to working on much larger transmissions with 3/4" bolts.

Thanks Jim

 

Jim, the threads in the plate are SAE, they do use Metric to attach the plate to the block, but those are drilled and counterbored.