Yes the crankshaft gear and has to be removed. You can probably borrow a puller from a part store like NAPA, O'rielly's or AutoZone.

@chip There is a video by Hagerty that you can find if you google “How we rebuilt our Chevrolet Stovebolt Six” at the 18:00 - 18:20 mark they remove theirs and the crank gear is still on. 

If I have to remove it, how hard is it to get back on? The manual just says to use a driver. I’m wondering if anyone ever taps the crank and pulls it back on?

There are some later model six cylinders that might not have to remove the crank gear. I use a block of wood and a large hammer to knock my crank gears back on. Tap on both sides in an alternate fashion. Be sure to get it fully seated. It is not hard just takes a bit of time to put it back on. Some have drilled and tapped pulleys or balancers that done fit the crankshaft tightly. There are also some sleeves that have been used or Locktite to secure them. Woe to the next guy that tries to pull the gear off next time if he doesn't realize it is there and know a little heat is needed to release the grip.

@chip Thanks Chip, I went ahead and pulled it this morning based on your advice. I’m sure this won’t be my last hang up. 

Main bearings, Cam & rod bearings, cylinder work are all in my future. 

Snag #2 

Chevs and The Filling Station are both telling me that main bearings and rod bearings haven’t been available lately and they aren’t able to predict when they will be produced again. 

Any other sources for these other than EBay? I’d be looking for stock size precision main bearings that don’t need line bored. 

Try Kanter.

https://www.kanter.com/

Depending on the condition of the existing babbit, you may be able to remove enough shims to obtain original tolerances as outlined in the shop manual.  I would recommend not using plasti gauge and instead  follow the procedure in the manual.  Search the old forum for senior members insight on the cam bearings. 

Kanter seems promising.

The existing bearings are a no-go. Agree with not using the plasti gauge. The procedure in the manual seems simple enough. 

I’ve been talking with a machinist and my be able to drop the block and crank at his shop next week. Based on my description he’s thinking 30-40 over on the bore and at least 10 under on the crank.

@tiny I talked to Kanter today and they told me that they do have some main bearings in stock. Are these bearings precision finished or are they partially finished and will thus need line boring? The gentleman I spoke with wasn’t able to answer that question.

I'm sorry Eric, I don't know. They are the people I bought my 38's engine rebuild kit from when I converted to insert bearings. You might check with Egge.

Eric, I had my '40 216 overhauled 4 years ago. The engine had over 400,000 miles on it, and the mains were ground 10 under. The main inserts were purchased from EGGE and bore-lining was not required. I was told then there was a specific year that inserts were made that no longer required bore-lining. I do not remember that year. If anyone does Chev-Gene knows.

@michael-l-deeter Thanks Michael. My understanding is that in ‘48 they moved everything to precision insert bearings and that anything purchased now (unless it’s NOS from pre ‘48) would not require line boring. I just want to double check that info, because I’m still very new to this engine and all of my research has come from searching this forum and others.

@eertle 

Your understanding is essentially correct.

However, there were some other changes made at the same time for 1948 (such as the width of the bearing which takes the thrust I believe).

That means the precision bearings you are looking for will fit 1940 to 1947, but are different from those that fit 216's from 1948 up.

Hope that helps!  🙂

Sure wish Gene was here.

@eertle I believe that is correct, any newer main bearings do not need to be line bored. I rebuilt myn 37 engine back in the 70s and did not have to line bore the main bearings.