olds engine related , useful info

https://oldsjunction.classicoldsmobile.com/oldsfaq/ofblk.htm

https://oldsjunction.classicoldsmobile.com/oldsfaq/ofhed.htm

http://wildaboutcarsonline.com/cgi-...itemid=9990378649894&categoryid=9970399476565

http://wildaboutcarsonline.com/cgi-bin/pub9990262549620.cgi?itemid=9990371596524

https://oldsjunction.classicoldsmobile.com/oldsfaq/ofinm.htm

http://www.v8volvo.se/mekartips/identifiering/oldsmobile/gjutnummer-block.html

http://garage.grumpysperformance.com/index.php?threads/looking-for-oldsmobile-id-info.11777/
OLDSMOBILE BLOCK CASTING NUMBERS

Blocks 1949 - 1964
The casting number is located at the rear of the bell housing.
The number are about ¾" high, and oriented to the right (passenger) side.

YEAR SIZE CASTING NOTES
'49 - '53 303 555614 Green
'49 - '?? 303 555641 Green
'54 - '56 324 568922 Green
568928
'57 - '58 371
'59 - '60 371 Gold
394 Green
'60 394 578135-4 1/8
'61 - '63 371 Gold
394 Lo comp: Green, Hi Comp: Red
'64 394 585786 This specific casting number seen on
an "Ultra-High Compression" engine.
The number "4 1/8" follows casting number.
Small Block Blocks 1964 - 1990
Facing the front of the engine, at the top surface of the timing chain area, to the left
of the oil fill tube, there is a code about 1.5" high followed by the casting number.
A letter indicates a big block, a number indicates a small block.
A small block measures 12" between the heads at the manifold base.

CODE YEAR SIZE CASTING NOTES
1
1A '64-'66 330 381917 45° cam bank angle.
2 '68-'76 350 381917
2 '68-'70 350 395558
3 '66-'67 330 394417 39° cam bank angle.
4
5 '73,'74 350 395558
2A '75-'81 260 Solid main webs for 2A's only? At least for '76.
2B '??-'81 260 557751 Windowed main webs. Windowed main webs for 2B's only?
3A '79 350
3B '77-'80 350 557752
4A '77 403 557265
553990
554990 Solid main webs possibly
for these three
casting numbers.
4B '77-'79 403 557265 Windowed main webs always.
?? '85 307 556607
5A '81- 307 3161
D3 350 7582 Diesel
Big Block Blocks 1965 - 1976
Facing the front of the engine, at the top surface of the timing chain area,
to the left of the oil fill tube, there is a code about 1.5" high followed by the casting number.
A letter indicates a big block, a number indicates a small block.
A big block measures 14" between the heads at the manifold base.

CODE YEAR SIZE CASTING NOTES
A '65 425 381917??
386525 1st year, big cars.
B '65 400 389298 442 only, one year only.
D '66 - '67 425 389244 Big-car engine.
Toro is different internally.
E '66 - '67 400 390925 442 engine [VERY rare].
F '68 - '70 455 396021 Common big block.
Stick type F (sans serif).
F '70 - '72 455 396021 Common big block.
Serif type F.
Two vertical and a base serif.
Fa '72 - '76 455 396021 Very common big block.
Marine also (L VIN derivative).
G '68 - '69 400 396026 442/Vista/etc. engine.
L '76 455 231788 Motorhome, marine and irrigation.
GM made motorhomes from '73-8,
maybe in all?
Casting number appears as "231
[tiny 'L'] 788" on the block.

Tillbaka

The Olds V8 Oil restrictors are iffy to me Grumpy.
Bearing shell mods I have done prior.

Done way different Pontiac V8.

Left The Olds 425 near stock.
Fantastic like I was told years back.

Olds had special lifters new.
Limit oil to top end.

I see them GM NOS for sale at times.
They sell for a small mint.

I was thinking of the Elbow crook return holes on 1964 & Up Olds V8.
It's actually 2 steps 2 tangent angles.
It's because the Olds V8 has 6 degree valve inclination cylinder heads.
Recall guys drilling out to 1/2 " inch the oil return holes.
Never been issue for me.

Pontiac V8 has generous cylinder head oil return passages. Non issue.