btbradley12

i am swapping a 350 to a 455

the car is a 72 cutlass s

it came with a 350 with a 2bbl and what appears to be an aftermarket water pump...

heres the issue... we took the motor mounts, all the pulleys, the fan and got a new water pump for a 72 350 and the pulleys didn't match up (rookie mistake getting a 5.5" neck rather than 5" but napa only had one listing) so we brought it back and did some research to get the proper length neck now the pulleys line up but they rub on one another.


starting to think that maybe the 350 is not from a 72?? looked up the casting number and it could be 68-74 block. the number that is on the front driver side just under the head is illegible (rebuilt block with ground off number?)

anyway looking for help to 1) find the actual year of the block so we can get the correct water pump or 2) just get the correct water pump

I have tried both new and rebuilt from napa (new one and rebuilt let us pick ac vs no ac) CAR IS NON AC car

there is a lot more knowledge here than can be found at napa thanks for your help

btbradley12

sorry the 455 is a 74 and the 350 oddly has an exhaust manifold casting number of 38001 (1963-1970?)

1970supremevert

just replaced a water pump on 71 455 non ac car, replacement pump was a gates 43120 new water pump, reassembled and had no problems, I had the same problem locating the correct pump at the parts house, luckily I had an original pump gm part# 384786

btbradley12

if i am using the 350 pulleys (they're in better shape than the ones off the 455) don't i need the matching water pump to those pulleys?

1970supremevert

https://classicoldsmobile.com/forums...p-lengths.html

maybe this post will help

Fun71

Look at the machined pad near the #1 cylinder. There will be some stamped numbers and the second number will be the year of manufacture.

This is from a '72 455 block:
P5060220.jpg


https://classicoldsmobile.com/forums...do-i-have.html
Head_ID.jpg



https://classicoldsmobile.com/forums...s-engines.html

P1010400-1.jpg

btbradley12

thank you everyone for the great info! unfortunately the first half of that number is ground off... so we did get the correct length water pump, however, the pulleys rub on one another (they are too close to each other) we used all the pulleys and accessory brackets off of the old block... only change is the water pump i know there are different length pumps but is there any reason for a different clearance between pulleys??

MDchanic

This makes no sense. The only way I know of for the pulleys to be touching is if the pulleys are mismatched to each other - pulleys of various diameters for various accessories were made over the years, and if you happened to have ones that were all "big" they might touch.

Which pulleys, exactly, are touching? Crank? Water Pump? P/S pump? Alternator?

A photo might be very helpful at this point.

- Eric

btbradley12

The car is not at my house so I do not have a picture right now... But it is the water pump and crank pulleys... At this point I am most likely going to give the water pump off of the 350 a try, it's not in great shape but it is not terrible either. The water pumps did not change in any way other than length from about 68-74 did they? I know there are some subtle differences but overall a non ac water pump should be a non ac water pump right? No reason for those two pulleys to become closer together like that only change should be whether it's a 5 5.5 or 6 inch shaft

MDchanic

The only difference in the dimensions of the water pumps is shaft length.

The distance between the crank and the water pump shaft is the same on both engines, so if the pulleys didn't touch on one, they shouldn't touch on the other.

Did you use BOTH the water pump and crank pulleys from the same engine?

- Eric

Allan R

All components of a 72 and 74 350 to 455 cooling should bolt directly from one engine to the other. How do you know the 350 2bbl water pump was aftermarket? The 350 2bbl non AC pump is a shorter unit with a different pulley than AC. Was the setup aligned properly on the 350 before you unbolted it? The crank pulleys on the 350/455 for 72 are identical for respective AC and non AC applications. I don't know if the 74 455 crank pulley is larger - that could be part of the issue.

I can find no such exhaust manifold in the GM Parts Manual. Exhausts should have a 6 digit casting.

Yes. That keeps everything lined up right. If you elect to go with an HD water pump (different length) you need to compensate by changing to the proper pulley.

I'd strongly recommend you visit the 72 Cutlass Assembly Manual and review the pulleys needed for the 350/455 engines with and without AC. Section 6-1, pages 90 and 92. That might help solve some of your problems.

BTW, as far as what year your 350 is? Assuming the heads are original to the motor, they should be #7. If they are something else, it may help indicate what year the motor is. That's not a guarantee of anything though. What you should check is the last 6 digits of the stamping pad. Compare it to the last 6 digits of the cars VIN. If they match, you will know it's the engine the car was born with, you'll also know then what the missing numbers and letter is on the pad.

btbradley12

Eric and Allan,

Thanks for the info and advice... this is my first endeavor into building/ restoring a car (im a 23 year old accountant relying on my father in law to be who is a chevy guy) I know i am asking a lot of questions so thanks for being patient...

i got the year for that exhaust manifold off the 442.com site (i missed a 0 on that number should be 380001) but like you said the heads are 7's and the last six digits on that pad under the 1st cylinder match the last six of the vin (how can i know what the rest of the numbers are on that pad??)

the water pump does not have a gm casting number on it, and it was put on using silicone rather than a gasket. this lead me to believe the engine had been rebuilt

yes, the pulleys were both from the 350 and were aligned correctly, however, i could only get the letters off of the water pump pulley... KN

thank you for the tip on the assembly manual; where can i get one?

thanks again guys

Allan R

Still no exhaust manifold with that number. Exhaust Manifold is in Group 3.601 LH - 403453, RH - 398704

To know the missing letters on the stamping pad is simple. Since you know the last 6 digits match your cars VIN, the missing digits will be
3 - Oldsmobile
2 - Model year (1972)
(M - Lansing, R - Arlington, Z - Freemont, or G - Framingham) - Production plant. Look for one of these in the plant identification of your VIN. Your 72 VIN should start out like this: 3G87H2(Letter)XXXXXX. The X's are the cars last 6 numbers that match the block. The missing letter on the stamping code will be the letter in () above

Ok, the water pump may be a replacement. Installing with silicone? Are you sure it wasn't RTV or Permatex? Those are acceptable liquid gasket compounds, but just replacing a water pump is no reason to suspect engine rebuild. Water pumps are common replacement items

KN is the large 2 greave water pump pulley for 72 350 and 455's. If you installed an HD water pump that will cause a problem with the way the pulley lines up. The crank pulley for 72 350 is KB.

Order off the web. All of the Assembly Manuals are reprints now so look for the best price and shipping.
eg: http://www.ebay.com/itm/1972-CUTLASS...32ecd8&vxp=mtr

Fun71

Actually, the outlet diameter changed in 1971 to a smaller diameter. The '68-'70 pumps have a 2" inlet and the '71-up pumps have a 1 3/4" inlet. I found this years ago when trying to swap the radiator from my '70 Supreme onto the '71 convertible.

foo

I don't mean to take this thread over But I'm having the same problem Im not swapping from a 350 but, my KN 2 groove large pulley is hitting my KJ crank pulley, and to top it off they are not lining up ether,both pulleys are repos from fusick I have the original KN pulley and it hits too I'm using a gates 43120 water pump as well.
(pics down below)

They are not the original pulleys I'm wondering did i order the wrong something, size pulley or pump?

Im using a 73 455 block mocked up to look like the 70 engine Non-AC going into a 70 442,





They are hitting

Allan R

KJ and KN are the pulleys for 1972 455. In this case it looks like your water pump is the issue, not the pulleys. The gates 43120 water pump is listed for up to 1970 455 applications, but the pulleys from 1968-1970 are different letter codes which makes them slightly different (likely a different diameter).

The water pumps for 72 455 w/o AC is 5.57" from block to pulley surface. The ones for 1970 are 5.094, so that looks like your issue right there.

foo

if its just the wrong pump, and the only thing that changes is the shaft length doesn't that mean its still going to hit the crank pulley? The codes for the pulleys are used on the 70 as well according to the 70 build sheet

Allan R

Only thing that makes any sense to this is the snout on different water pumps may be at different heights also. Your pulleys greaves to look to be out by the amount of the noted distances already posted.

foo

ok so i ordered a 5.5 to replace the 5.07 just to check and it is too long, Im starting to thank the the harmonic balancer isn't seated all the way though I tried to press it on more it did not move any, any ideas? here are the picture of the balancer as it sits in side and out





does it look right?

MDchanic

Hard to see from the pictures, but it looks like the balancer is about an eighth of an inch out from the end of the crank.
That shoulder inside the balancer should be flush with the end of the crank.

Did you tighten the crank bolt to about 200 ft/lb?

This will not make the pulleys not touch, but it may make them line up.

- Eric

foo

I used the balancer press to put it on and put my full wieght into it and had the bolt to around 160 ftlbs

Allan R

160 ft lbs is the minimum torque spec for the HB according to the 72 CSM.

foo

I think that was as far as my torque wrench went

MDchanic

Are the shaft and the inside of the balancer completely clean and free of burrs?

- Eric

foo

yup, I will be taking it off again tomorrow and setting it back in and see if it goes, I think I messed up on one of my steps by placing the key on first and its binding it up before it can seat all the way if that sound correct

foo

as far as i can tell every thing is as seated as it can get. I pulled it all down right to the timing chain and everything its as far back as it can go I measured the shaft length from the front of the timing gear to the end and its showing that its shorter than the balancer so I'm clueless on what to do now and very frustrated now

tru-blue 442

Foo, if you can find a 399405-KC
crank pully and a 399404-KF water pump pully
with the 5 1/2" water pump, you should be good to go.
These are for a 70 455 with A/C.

OK, nevermind. Looks like you are running
2 belt pullys. No A/C, correct?

foo

correct no ac, with 2 problems of them hitting and not lining up

tru-blue 442

Is your H/B flush with the crank
using the big flat washer and bolt
to drive it in?

foo

thats the current problem im trying to figure out because it will not sit flush if you can see from the pic above its about 1/8 inch out or so, that's when I started pulling everything apart, I will take another look at it tomorrow when Im alittle less angry. Ill press on the HB with out the cover on to tell is its seating all the way

the timing sprocket does not sit completely flush with the crank there is less than a 1/8 inch behind it my tape measure end caught in it, the sprocket itself is 1in. on top of that you have oil splatter wheel and from what i can tell the HB was in contact with it so it wasnt going any further in.

foo

Messured stuff to day and here is what i got, end of crank shaft length is 3 1/8in, sprocket is 1in, H/B shaft its 2 1/4, plus whatever the oil splatter wheel is it hangs off the end 1/8in or so, does that mean i may have a wrong H/B?