I am swapping out a 350 Rocket for a 1969 Oldsmobile 455 engine in my 1970 Oldsmobile Cutlass. I am swapping all of the engine brackets and accessories from one engine to the other including the A/C brackets and compressor. The water pump and crankshaft pulleys are not lining up since the 455 apparently was in a car without A/C. I understand there are three options for water pumps which have lengths of roughly 5.0, 5.5, and 6.0 inches. The 5.5 inch long pump goes into A, B and C bodies with A/C and the 6.0 inch long pump goes into an E body car with A/C according to my manual. It appears I need the longest water pump to make the pulleys line up properly.
I am wondering why there would be a difference between the pumps used for cars equipped with A/C if the dimensions on the 455 engines are supposed to be the same regardless of which body style they go into. Is there a difference from one engine to another depending on whether it was in a cutlass, 88 or 98, and a Toranado? If there is a difference, is it in the crankshaft and harmonic balancer and how far it extends forward from the engine?

 

Why ask why?

Just swap your 350 water pump as well, and you will be happy .

Curiosity killed the cat.

- Eric

 

Yup and use all of the pulleys from the 350. All you'll need to do is replace the alt and A/C belts for ones from a 455 and you're golden.

 

I asked these guys the same questions along with a hundred others before me.

 

Haha so I am not just crazy. That is good to know. Thank you for your help MD and svnt.

 

I checked the water pump from the 350 and it is not long enought to make the pulleys match. From what I can see, I need to order the longest pump to make the pulleys match which makes your statement above not true.

Another difference I discovered what that the fuel line from the fuel pump to the carb is different. I am pretty sure I read somewhere that the intake manifold on a Toranado 455 was lower in profile than the intake manifold on a 455 from a 442, 88 or 98. This would explain why the fuel line ordered on line does not work as well.

 

Let me try this again......use the water pump and the pulleys from the 350. Do not use any of the pulleys from the 455.

I've been doing this stuff for years and so have most of these other guys so we know what we're talking about.

 

Exactly.

Don't mix and match. - All from one motor or all from the other.

And, yes, for a Toro manifold, you need a Toro fuel line (or some creative bending).

- Eric

 

If you used the same brackets, pump, and pulleys from the 350 and the pulleys don't line up, then you have the brackets installed incorrectly. The fronts of the 350 and 455 motors are IDENTICAL and the brackets fit both. The only difference is the deck height, and where this matters, the brackets have two sets of holes to fit both motors. Did you reinstall the two spacers between the PS pump bracket and the block?

 

it fits like a glove,

did it also in a b body 69 delta used all the parts even the oil pan without problems.

only dameged the pulley from the steering pump.

 

I didn't mean to tick anyone off. Just trying to figure out what I'm doing wrong.

I switched everything from one engine to the other. I will check to see if the harmonic balancer is properly installed as well.

The only pulleys that aren't lining up are the crank and water pump and everything else looks fine.

Does anyone know why there would be two lengths of water pumps for a/c cars depending on the body style?

 

You didn't swap the balancers, did you?

- Eric

 

the lenght off the waterpump are differend, so if you used the 455 waterpump and the 350 pulleys it could get a wrong offset.

 

the balancer doesnt affect anything
i swaped all the stuff and mounted it on the 455 becouse it was the cheapest way.

the only thing i had is the using other hole on the alternator bracked and you need longer belts becouse the deck is higher

 

https://classicoldsmobile.com/forums...tml#post177949

so you can see the differend waterpump snout lenght.

 

Wow Im glad this came up because Im going to do the 350 t0 455 swap here soon and was hoping everything swapped over.

Matter of fact, I took all my brackets and pulleys (for my 350) off a 79 V8 260 and they matched perfectly! Lovin Oldsmobile for this!

Most of my Buick buddys are buying all new distributors, water pumps, etc. to do the big block swap!

 

I did the swap, and just re did it because of a spun crank bearing. I had a 71 350 with AC, now 70 455 and I just put the 6 inch water pump on with the orig 350 crank pulley, and water pump pulley. Both those and the altenator line up perfect. The only issue I have is the power steering pump lower mount spot on the block does not line up. I still need to make a little tab for that its 1/2 inch off or so. What ever you do don't change out your motor mount frame plates. I had 455 mounts with 350 plates and it worked great, you couldn't get the oil pan off if you tried but thats ok, I just put BB plates and it raised my motor so high that I have to move my brake booster over to get my MT valve cover on.!! Good luck with the change over. Take deep breaths and throw a wrench at the wall every now and then.

 

I've said it before, and I'll say it again....you can't use bbo mounts with sbo frame brackets or vise versa because they won't line up. You'll get one side bolted in and the other will come nowhere close to bolting up.

They are NOT interchangeable. You have to use the frame brackets and engine mounts as a set.....peroid.

 

So im gettin closer to my install and just want to make sure.... Do I need to buy big block frame brackets? I was going to purchase the bb motor mounts soon and want to make sure. Thanks

 

You don't NEED to buy anything. Use your existing SBO rubber motor mounts, the existing SBO frame mounts, and the 455 bolts in exactly the same way and in exactly the same place as it would if you had spent all that money on new mounts. See this thread:

https://classicoldsmobile.com/forums...tion-list.html

 

Sweet! Im in tears of joy right now! Thank you for your helping me save some much needed cash.

 

Example....

I had an 80 Cutlass that came with a 260. I swapped in a 350 for a few years until I beat it to death and then found a 455. In that went on the same mounts. Then that tossed a rod bearing 1 MONTH later (damn it) and I did another swap back to a 350.

All of this was on the same brackets, motor mounts and exhaust. Bolt in and go.

 

And to add to that, EVERY 1964-1990 Olds V8 (except the 64 394) has the motor mount attaching features in EXACTLY the same place relative to the crank centerline. BBO, SBO, diesel - they all have the same features in the same place.