383 Pilot Hole Dimensions?

I've searched all over the internet, and i swear that every post i came to asking this questions had 10 answers. And there all different!

Anyway i've got my crank at the shop getting its main's turned down and i want them to drill the hole deeper if it needs it.

It has a pilot bushing in it, but i don't want any surprises when i get the bellhousing and am ready to put it all together.

The outside diameter of my pilot bushing was about 0.9" and the hole from the end of the pilot bushing is about 1.7" deep with a slight taper at the end.

will this clear the transmission shaft, because i refuse to cut the the input shaft?

thanks

-Lucas

The end of the crank has a stepped bore, the outer finished diameter for the bushing is .9375"....the rest of the bore forward of that only needs to be larger than the .750" input shaft pilot.

You're good to go.

All of the 4 speed cranks I have are 1.750 deep. You should be good to go. The diameter is the main thing. Not sure of that one but I bet John is correct on that.

15/16"
Near the bottom of the first page of my 505 stroker buildup, I mentioned having to drill the crank for the bushing:
https://board.moparts.org/ubbthreads/show...part=1&vc=1

As i mentioned it already has a bushing in it, so i imagine the diameter is correct (or someone has figured out a way to insert one), but i'm really concerned about the depth. I guess 1.75" is about the factory depth for a 4 speed pilot shaft.


we'll see when i get the bellhousing.

You are worrying about nothing.
Think about it, the machining operation to ream the hole for the pilot bushing to fit in is the last operation. By then the crank has been drilled, probably by a single stepped bit with two diameters. And you'd better believe that there was NO TIME to do any fixes when the engines and transmissions were being put together. So if it already has a pilot bushing in it, it has a hole deep enough for any transmission shaft they were using. For that matter, the hole was present in almost automatic cars until at least 1970, just not reamed. There was a special diameter pilot bushing you could get from NAPA that was for the non-reamed hole, if you were putting a stick behind a factory automatic engine. But many many automatic cars will have a pilot bushing hiding in the crank under the torque converter nose.

In any event, the hole is deep enough.

R.