Putting a 263 into the '40

[Guest mattmckean74]

I have picked up a 263 with an automatic and am going to try to put in the '40 Special over the Thanksgiving holiday... I am wondering what problems/ issues I am going to run into... As always, I appreciate any help guys!!!

[Pete Phillips]

I could be wrong, but I think the 263 is a little bit longer than a 248, in which case you will have clearance problems with firewall and radiator. Another problem is that you will have to totally rework the engine mounts in the '40. The 263 has two "feet" that stick out of each side of the engine, about midway down the length of the block, and that's where it mounts in the car. The '40 engines have the motor mount on the front, just behind the crankshaft pulley. So unless you are a good fabricator, you are going to have problems.

Pete Phillips, BCA #7338

Leonard, TX

1949 Super Estate Wagon

1950 Roadmaster 2-dr. ht.

1959 Electra 2-dr. ht.

1962 Electra 225 4-dr. ht.

1963 Wildcat conv.

[1939_Buick]

I am sure 263 same lenght as 248. The old guy has a 263 in his car [ the 320 is longer ]

For front mounts you need to use the from plate of the old motor. It may bolt up

The "auto" may the hard part: you wil need to get your manual transmission / clutch to fit

[The Old Guy]

I have a 263 in my 40 as the gent from Australia said, and the only problem i can forsee is the automatic has a different flange on the back of the crank. I don't remember what the difference is ,but I know there is one.

[Guest mattmckean74]

Ok guys... So far, I am looking at having to change out the front plate to get the forward mounts transplanted... as for the flange differences on the crank... Does that mean that I will need to change out the crank and/or is this even feasible? Will the 248 crank fit in the 263? Are there any differences in main or rod bearing dimensions? Any differences in stroke? As always, thanks for all the help guys!!!

[50jetback]

Matt,

Your biggest issue is the crank. Because your 263 has a Dynaflow fitted I believe the end of the crank won't be drilled for the pilot bush/bearing for the manual gearbox main drive shaft. Somewhere on this Forum this has been discussed - inability to match crank from Dynaflow engine with manual gearbox. my parts book also shows different part numbers for cranks - Dynaflow V's Conventional transmissions.

Looking at the crank bearing comparisons 1950 Series 40 and Series 50 motors ( 248 V's 263 ) they are different according to the workshop manual.

Sorry I haven't supplied a solution but I think the only option is to source a 263 motor which came factory with a manual gearbox, or at least the crank from one.

[Guest mattmckean74]

Ok... So changing out the crank doesn't sound like an option at this point... What about putting the automatic in the car instead of the manual? Is this feasible?

[Ben Bruce aka First Born]

Feasible but not easy.

I believe, if you want to stay with the standard, the crank can be removed and taken to a reliable machine shop and the pilot bearing hole machined into it.

Ben

[Guest mattmckean74]

Thanks Ben... I remember reading something about this in an older post, but can't find it!! Are there any differences in the flywheel flange bolt patterns?

[Guest mattmckean74]

Funny talking to you now Ben... Was just sitting here reading your old post about rebuilding the 248 and all the help that you got from the guys... What mashine shop did you use for all of the work on your engine?

[Ben Bruce aka First Born]

Matt, I used O'Rileys here in Springfield, MO. They did a great job. I would have to believe there is a good automotive machine shop near you. Perhaps in Peoria..

Stay with us. Don't let it whip you. What I have found out is that there is very little that is "first time". Some one has already mastered this problem. Just maybe not quickly.

Luck

Ben

[The Old Guy]

Another thing to think about is the bell housing. The bolt pattern is the same, but you will need to indicate the hole where the trans fits. That hole is finish bored after the bell housing is mounted on the block. The dowel holes were not always the same as the machines of 70 years ago were not as good as what we have today.

If you do not have the manual bell housing that came with the engine, remove the dowels ,bolt the earlier housing to the engine and tap it around until you get a 0 reading. Then use a tapered dowel pin reamer or open the dowel holes up and fabricate oversize dowels.

If this is not done you will have a Buick that will have a tendency to jump out of gear when you let off the gas.

[Guest mattmckean74]

Thank you VERY much for that one "Old Guy"!!! Definitely don't need to be jumping out of gear!!! Had a car once that used to jump out of gear all the time on the interstate!! Damned aggravating!!! Am thinking seriously about that automatic though... Anyone out there have a retrofitted Dynaflow on an older model?

[WWS]

I was told tonight, by the person who is putting a 263 into my 46, which like your car had the smaller engine, that putting a Dynaflow drivetrain in place of the whole manual system is a nightmare and a real pain in the tush.

Better to stay with the manual trans, unless you are really good at fab work.

Machining a crank is an option, but you need to be sure they are qualified, otherwise you trash a crank and start another search, and spend even more dollars.