Stroker Olds or Cadi Swap?

565bbchevy

565bbchevy

Geezer
Aug 8, 2011
6,215
5,274
113
Michigan
#31
If you are just going for a nice cruiser with an ample amount of power I think if you can find a donor car with a 500 Cadillac to get all of your accessories etc. that would be the way to go and if you crave more power later on as the budget allows you can then upgrade to some nice heads and cam etc.
You figure you are starting with 150 extra CI from the Cadillac with no special machine work or parts to get there and the performance aftermarket support for both the Olds and Cadillac are probably somewhat comparable.
 
K

Kennybill

Greasemonkey
Mar 17, 2010
152
121
28
Braceville, Ohio
#32
Back 15/18 years ago I sold a set of Olds 425 7" rods to a Cadillac guy. He said the "hot" ticket (cheap) upgrade for the Cadillac rods (rubber bands) were the Olds 425 rods.
The 1965 & 1966 Olds 425's are 45 degree lifter/camshaft angle. These are standard diameter 0.842 lifters and you can get 45° camshafts. I've had four 1967 non-Toronado engines and all have been 39° degree engines.
Stay away from the 1968/1969 Oldsmobile 400 engines (G-block) the bores are too small for proper valve unshrouding. The 1965 Oldsmobile 400 cu/in was a B-block (4.00" bore and 7" rods) great engine. 1966 & 1967 Oldsmobile 400 engine was an E block engine, 4 inch bore, 7 inch rods, 39° camshaft angle with the Toronado/442 Lifters 0.921 inch "big lifters." These "early" 400's had the same crankshaft as the Olds 425.
If you find a early 400 engine, get if touch with me, I'll fix you up with your choice of 403/425/455, just saying.
 
C

Carson L W

Not-quite-so-new-guy
Dec 3, 2017
15
2
3
#33
Does anyone know if the olds 455 crank would fit just like a 425 in a diesel block? Or are the counterweights too big?....
 
fleming442

fleming442

Geezer
Dec 26, 2013
6,159
7,054
113
#34
Yes, just like the 425 crank, the counterweights are too big. 425 cranks are preferred because they are forged steel, not cast iron. 330 cranks are also forged, don't require the turning down of the counterweights, but require bearing spacers on the mains and are limited to 3.5" on a Chevy rod pin. Honda 1.88 will get you a little more.
Not sure if my math is right, but 2.1-1.88=0.22/2=0.11+3.5=3.61 stroke on the Honda journal?
 
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C

Carson L W

Not-quite-so-new-guy
Dec 3, 2017
15
2
3
#35
The 455 would have more stroke than the 425 crank, but would I be able to turn it down enough to clear?
 
olds307 and 403

olds307 and 403

Comic Book Super Hero
Oct 14, 2008
4,380
2,156
113
Melville,Saskatchewan
#36
I believe the 455 crank will not clear the 350 block.
 
rogue_ryder

rogue_ryder

Apprentice
Oct 27, 2017
97
196
33
Colorado
#37
there's plenty of info on how to build huge horsepower Olds Diesel block based engines over on RealOldsPower.com If you've got the money go for it.

I would not do a Caddy 500 build (I almost went down that road), complete good running 500 motors are cheap and enticing but they don't rev, they just make a mountain of torque. Great for moving big old Caddys but not really a fun engine nor a race engine IMHO. There's some good recipies for BBOs out there; but it's gonna cost you a mountain of cash to build one up that will be reliable. Then there's the whole cost of beefing up everything else along with the BBO (Trans, rear end, etc.). If you have AC in the car, there might be slight clearance issue with the condenser that comes out of the firewall with the BBO too. Otherwise the BBO is a bolt in for the Gbody Cutlass.

I think the smart money is converting the DX using spacers and 330 crank. They aren't that uncommon I found one for my project within just a few weeks of looking. It's been ground, balanced, nitrided and polished and I think I've got around $600 into it total. That 330 crank won't give you the 442 cubes but it's a hell of a lot cheaper than the machine work involved using a 425 crank. It's the only Forged SBO crank that I know of. The N marked cranks are supposed to be decent as well. Mark Remmel has built serveral engines for people (Cutlassefi over on ROP) and sells parts (rods, pistons, cams etc.). I'm getting real close to wrapping up a 403 build based on one he did that was good for 450hp on a dyno. The SBO doesn't have the oiling issues the BBO does either, it's lighter which is nice in light car like the Gbody (well light compared to an Abody).
 

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