Hot Rods 426 HEMI flywheel bolt size question

Starting on another engine build for the next family Hot Rod this time its going to be a sixty's power plant. The engine is going to be a 426 HEMI so I'm now learning some of the details involved this week I'm working on a transmission adapter.
My 426 stock stroke crankshaft has the 8 bolt hole crankshaft flywheel flange the holes are 1/2 -20 thread. My question is did the 426 HEMI ever come with a 7/16 fine thread bolt hole ?
Ronnieroadster

 

I’ve used the 1/2”-20 thread hemi bolts on my GMC’s 6’s for years. I never saw a listing for any other size…

 

All I had were 1/2". I used 413 industrial cranks sometimes and they were 1/2". The industrial crank has a longer flange that requires a 392 length input such as when you use a Lenco.

 

Thanks for information the transmission conversion I'm using came with 7/16 hardware for the crank flange but the flywheel and crank spacer both have the correct 1/2 inch holes. Should be a simple correction. So yesterday I contacted the adapter people about the difference now waiting to hear back about if they will be correcting this by supplying the correct bolts.
Ronnieroadster

 

early Heni were 7/16

 

A smart man might look up the ARP bolts in the size and length he needed, then ask the supplier about those exact part numbers...

 

All ate Hemis are 1/2-20. What are you adapting over to? Mopar made some decent transmissions that will bolt right up.

 

The wife requested an automatic I want the overdrive option as well. So I need one that will handle at least 600 HP and similar torque numbers. Unfortunately there's no good options for that with the Mopar automatics with overdrive that are not computer controlled transmissions. . I don't want computer controlled anything on this build so Im going to use a different brand.
Ronnieroadster

 

Originally nutted studs went through the crankflange, might have been 7/16, but you have to run a 1/2-20 tap though them and use the 426 Hemi flex plate/flywheel & bolts.

 

The 46RH isn’t computer controlled,,,,,and it’s a great transmission .
It’s a 727 with an overdrive,,,,,but controlled with hydraulic pressure .
There is a simple switch system that is used that operates off of pressure from the governor .

Tommy

 

That's what I have behind the Cummins in my '93 1-ton. No computer at all.

 

Thanks for the info about the 46RH but its way to long don't know of anyone using it in a Deuce. So I'm staying on track with what I'm working with.
Ronnieroadster

 

A 727 with a 2.47 rear end... with that engine you'll still be traction limited!