Crank hole for pilot bearing

[nate428t/a]

Hi all, long time no post.

I finally made time to get deep into my Tremec TKX 5 speed swap (Silver Sport kit) on my '79 and I have hit a snag, hopefully not a brick wall. My car has a 1969 428 in it and I am replacing the TH400 that the prior owner had swapped in with the engine. once I got the auto trans and flex plate out of the way I started to size things up to start bolting things on.

My problem is that the machined hole/pocket in the crank (see picture, second "step" into the hole) for the pilot bearing is, as near as I can measure about 1/16th of an inch too small for the pilot bearing SST sent me.  I would assume that I should be able to wedge it in a little bit, but it is definitely not going in there, but as I said, it is really close.

I read somewhere that some Pontiac cranks were not machined to accept a pilot bearings if they were going into auto cars. I was hoping if that were the case for me that it would be more obvious, but it is pretty close, but definitely too small. 

I sure don't want to yank the engine if I'm just doing something wrong. 

Does anyone here have any ideas what to look at/for? Thanks.

[phil400]

I know when I did my clutch I put my pilot bearing in the freezer the day before to make it easier to drive it in.
Only thing I could of is maybe try and find a pilot bushing( not a. Bearing) with the correct size for the trans shaft and turn it down on lathe to fit your crank. Sorry not much else I can think of.

[scarebird]

I would get a cheap digital caliper and see exactly what you are dealing with first.

Rockauto shows an outer diameter of 1.378 for a 69 428.  Also check the diameter of the pilot - should be 0.591"

[nate428t/a]

Did all kinds of digging around the internet on this one, and it seems like the bronze bushing is the best way to go.  I did get a call back from SST, and they agreed that it is acceptable, so that's a relief.  The ID of the pilot is 0.591 or right at 15mm, and that fit on the trans shaft just fine. I will go with bronze and get good measurements on the hole while consulting with a machinist to get it turned down if that ends up being necessary.

Thanks for the input.

Here's a closer up shot of my crank... (never thought I'd say that on the internet)

[scarebird]

...Here's a closer up shot of my crank... (never thought I'd say that on the internet)

yeah, well you are going to need to clean up your crank hole before you do anything with it...

[nate428t/a]

yeah, well you are going to need to clean up your crank hole before you do anything with it...

Sage advice.

Divider calipers showed up yesterday, and I have a telescopic snap gauge coming too. The bore is almost dead on 34mm as close as I can tell without a micrometer. My Vernier calipers have a digital readout that goes to the hundredths, just need a new battery there. the bearing is stock sized 1.38 inches or 35mm. 1mm is 0.04 inches, so I'm way over what you could expect to press in. I'll measure about 100 more times before I get anything cut.

[silver78]

If you haven't already done this step, I used lakewood adjustable offset dowl pins (yeah expensive) to get the .005 transmission alignment required in the bellhousing center bore.  Im in the same phase as you with my tkx swap and the hurdles just keep coming. SST has been great to work with highly recommended!

these are less expensive if needed.
https://www.robbmcperformance.com/products/dowels.html