I will be replacing my original 350 2bbl with a rebuilt 1969 455 Toro engine in the next several weeks. My neighbor will be helping me with the swap.

1. Can I reuse my 350 engine mounts, or is it advisable to buy new replacements. I believe I have seen p/n 2261 or 2262 referenced in the past for b/c body only. Which one is correct for my application?
2. I understand that that the 455 is slightly wider and possibly taller. I'm currently running true dual exhaust on my 350 using Thornton S manifold on drivers side. I plan on reusing this manifold on the 455 along with a Thornton W manifold on the passenger side. I'm concerned about manifold to (existing) exhaust alignment issues. I'm thinking exhaust pipe connectors will need to be modified but not sure how.
3. I'm keeping the Th350 Trans, which has been problem free. The 455 is a mild rebuild with stock pistons. Bores were honed along with new replacement rings, rod bearings,HV oil pump, Cloyes double roller timing chain, ATI balancer rebuilt C heads, Edlebrock Performer Intake, plus Edlbrock Cam and Lifter kit. Quickfuel 750 vacuum carb and new aftermarket Block distributor.
Engine was factory rated at 375 hp, but im curious what I ended up with hp wise?
4. Engine still needs to be broken in, but I don't have access to s run stand. We may start it briefly on the engine build stand, with valve covers off, just to make sure there are no strange noises etc. before the transplant.
I appreciate any input about things to look for.

 

The full size cars use the same mounts no matter what size engine. Anchor 2262/2263 if you need new ones (they are RH/LH since the stud is offset).
You need the S manifold to clear the steering box. The matching manifold for a BBO in these cars is casting no. 398708 "T", which requires a cap for the crossover pipe opening when running dual exhaust. The repro cap for the small block manifolds does not fit. I made one from a section of the crossover pipe. I have no idea if the W will work or not.
The TH350 will bolt up, but how long it lasts is up to your right foot. Obviously a heavier car puts more strain on the trans. You'll need a long-tail TH400 when the 350 frags.

 

Appreciate your feedback Joe. I'll report back on any fitment issues with the passenger sideThornton W manifold.
I had originally planned to do the 455 swap last spring, but couldn't pass up the opportunity to purchase a 1957 Golden Rocket 88 in early March and which required more work than I had anticipated.

 

Take a look at which rear end your car has, good chance it's not the big block 9.375" gear.
But being a rag , maybe?

 

Good point. The 350 cars came with the 8.5" Type O in 1968.

 

Delta 88 SBO, 8 7/8" 10cover & 12carier ?

 

Olds dropped the 8.875" Type P axle after the 1967 model year. The 1968 CSM clearly shows the same Type O 8.5 for all 3100-4800 (A-body cars) in addition to the 5400 (350-powered Delmont).

 

I have a TH400 long tail out of a '68 98 that I parted out and am somewhat local. (near Madison) I also have the BBO manifolds (and lots of other stuff from that car too) Shoot me a PM if interested

 

I was under the impression we're discussing a '69 B body 5467 SBO .
Not the 10/10bolt 67 Cutlass
Thought the '68+ 10/12 8 7/8" B car SB continued well on in the 70s

Good to know

 

Are you planning to sell the 350? If it's still in decent shape and reasonable priced, I'm interested. Thanks!

 

You're right, this thread is about a 1969, not 68. My mistake. The 1969 CSM also shows the Type O 8.5" axle used in the 5400 series cars.

From the Parts Book also. 66-67 5400 series DID use the Type P axle (blue arrows). 68-70 5400 used the 8.5" Type O (green arrows). Note that the carrier part number for the 5400 is the same as for the A-body cars.

 

That's a great reference, maybe it's how you cropped it but I see the 5400-6800-8600 '71+ , don't see it for the '67-70 9.375" 455.

 

Look at the line directly below the bottom green arrow. 230387 is the 1968-70 full size 9.3" Type O for 2.56 gears. The line directly above that last green arrow is the 67-70 full size Type O for all the other ratios. 230052.

 

EYes open

I would think ..049-..052 are all small gear A body, only one listed as 9.375" , ..387 , which brings up another 2-3 series gear carrier question.
And apologies for getting this off track, but it might help the OP.
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Sorry, but you would be incorrect.

 

So it's pretty much established that OP's car has an 8.5 Type O as it sits. These Type O's survived quite well in 455-powered A-bodies. Is the extra weight of the B-body that much of a factor or is there something I'm missing?

 

From what I see that isn't a 8.5" A body rear but a '68+ 8 7/8" B Body SBO rear. The rest mentioned are A body with the exception of possibly one 9.375" as non F85 and implied B and C body and the 9.375" big car B C body 71-76. Both 31 spline axels except a different spline angle on the 71+ and a couple other differences as a whole assembly. Only big block cars for the most part had 9.375" in the B and C.

 

Sorry but you are still wrong and are spreading misinformation. There were only TWO axles used on US-built Oldsmobiles in 1969, the 8.5" Type O (12 bolt cover, ten bolt ring gear) used on all A-body cars and the 5400-series B-body cars) and the 9.3" Type O (12 bolt cover, 12 bolt ring gear) used on all big block full size cars, period. Yes, the Chevy 8.875" 12 bolt was used on Oshawa-built Cutlii, but that obviously doesn't apply to the full size being discussed in this thread. There was no "8 7/8" B-body SBO rear end" after the 1967 model year.

 

Ok , the references I've seen then must be incorrect. But more than one, and truth is I've seen conflicting information on these and going forward other big cars Buick etc with big blocks not using the 9.375", and stubborn arguments on the topic.

Misinformation isn't the inten, I hope you know that.
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Buick, Olds, Pontiac, and Chevy B-body cars used completely different axles, suspension, brakes, and frames on the 1965-70 cars. What Buick may or may not have done is irrelevant to Oldsmobile.

 

RIght , wasn't referring to mounting position or the like. So no 8 7/8" SB B body Olds rear or other in that application, only 8.5".


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Pretty sure I've now said that three or four times in this thread...

 

Yeah I just learned something, thanks for the clearity.
It's all there, now that I see it again.
But I'll need to check on why a non Chev 8 7/8" 250 casting 10/12 31 spline was in a 350 Delta original.


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Did I miss the part where anybody addressed my question? It might be useful for OP to know.

 

Yes, obviously a heavier vehicle puts more load on the rear axle for the same amount of input torque. Of course, it also depends on how much of the torque is actually absorbed by the gears as opposed to being lost spinning the tires. If traction is the "fuse" then breaking the axle is less likely.

 

I learned today that the 69 Toronado engine oil pan sump interferes with the steering linkage on my Delta, so it I need to swap out the oil pan.

The passenger side S manifold fits perfectly to existing exhaust.

The drivers side W manifold interferes with the column shift linkage. Fortunately I have converted to a 1970 floor shift, so i can cut out the column shift linkage.