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Are the early 1953-54 full oil pressure 235 crankshafts the same as the 1955-62 crankshafts?

My Federal-Mogul master bearing catalog lists the following crankshaft forging numbers for 1954-61 235 and 261 engines with the same connecting rod and main bearings for all of them:

3701486
3701488
3701488A
3770327

Jerry

Yes, all full pressure 235 and 261 crankshafts are the same.

An engine builder friend retro-fitted a full pressure crank into my 40s truck 235. Had some machining to do on one of the bearing webs and redoing of oil supply plus later oil pump. Not sure if this is where you are going with this question.
Best of luck
Jim

Gentlemen,

Thanks for the information. Just wanted to know what my options were as I am using a not as common 1954 engine. I like to have a plan "b" and "c" at all times if possible. I have several 58-62 engines and parts and noticed several differences in the evolution of the 235 and thought the crankshaft may have changed as well. If all full pressure 235 and 261 engines use the same crankshaft, why are there (4) part numbers?

Thanks again for the intel.

Paul

Over a span of several years of production it's not uncommon to have some number changes. I believe there are 8 or 10 casting/forging numbers for small block V8 cranks, and they all fit the 350 engine.

I will revise what I posted above.
I have seen a 1953 Power Glide crank that did not have the pilot bushing area bored out to accept a standard size bushing.
All 1954 and later cranks I have seen are bored for a pilot bushing. Chev would have given the 54 crank a different part number just because of the pilot bushing machining change from 53.
The cranks all interchange but in the case you have a 53 crank, and are using a stick transmission, turning down the OD of the bushing to fit the crank is necessary.

Is there a dimensional difference between the '53 dipper motor crankshaft and the later full pressure cranks??

John

The widths of the rod journals are different and so is the thrust journal width on the two cranks, other than that I don't know of any other dimensional discrepancies.

The journals are the same diameter but as 12 Port says, the main thrust and rod journals are wider on the splash crank.

So it sounds like it would be possible to change a '53 dipper to full oil pressure with a full pressure crank and newer rods and a bit of plugging here and there......

John

It takes some pretty creative machining on the block, since one of the main bearing webs and the corresponding main cap has to be narrowed so the drilled crankshaft will fit into the splasher block. Lipstick on a pig, sort of!
Jerry

There are not (4) part numbers.
3701486 is the part number for casting/forging number 3701488.

3770327 is the casting/forging number, part number 3770326.
This was a new crank in 1960 for the 261 engine.
Although it is identical to 3701488,
except it has a 7/16 x 20 tapped hole, 1 1/4 deep
in the front end of the crankshaft.

These special cranks were only used for the
crankshaft mounted power-take-off.

It provided additional support to the press fit
of the harmonic balancer to the crankshaft,
using a bolt and washer.

X2 on what Hotrod Lincoln said about swapping cranks. Too many people give the later engines away for free on here to warrant going to that expense and effort unnecessarily.

Gentlemen,

Been away for a few days. Thanks for the great information as it has certainly enhanced my Stovebolt knowledge.

Paul