billet a/c brkts

[Joseph44]

Hi everyone Question :I want to put a/c  in my 76 442 can anyone tell me if the olds 455ci motor and the 455ci Pontiac motor if the blocks are the same. I don't know which motor is in the 442 so what I need to know is do they both take the same brkts with the same bolt pattern I'm talking about the compressor brkt. Any help would be greatly appreciated. Happy cruising.

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[joe_padavano]

Every GM division at that time used COMPLETELY DIFFERENT motors, despite the common displacements.  Different bores, different strokes, different architecture, different castings.  NOTHING interchanges, except parts like the distributor cap, rotor, and carb base gasket.  Your car came from the factory with an Oldsmobile-sourced 455.  I have no idea what is in the car now.  The fact that the Olds motor has ten bolts per valve cover and the Pontiac 455 has four should be a hint.  The bolt holes for accessory brackets are also completely different. If you are looking for a nice bracket to bolt a Sanden compressor to an Olds motor, Classic Auto Air makes one.  It is not billet, just steel.  It has a considerable amount of adjustment for belt alignment.

 

Note that if your Olds currently does not have A/C, you will need to get longer high volume water pump, the matching three groove pulleys, and the correct brackets to relocate the alternator to the driver's side.

 

And yes, in 1975 (not 1976), Oldsmobile DID use the Pontiac-sourced 400 motor in a few applications, but those were only in the full size cars, not in the Cutlass line.

[Joseph44]

Thanks Joe for your input I'm going to have to locate the cereal number just to be sure but you pointed me in the right direction. Now all I need is the location of the block number. Thanks again and keep on cruising!

[joe_padavano]

21 minutes ago, Joseph44 said:

Thanks Joe for your input I'm going to have to locate the cereal number just to be sure but you pointed me in the right direction. Now all I need is the location of the block number. Thanks again and keep on cruising!

 

You'll find the "cereal number" from Kellogs...

 

If you are looking for a casting number, it is on the "shelf" above the water pump, next to where the oil fill tube enters the block.  If it's a 455, the number will be 396021. Every single big block Olds motor has exactly the same bolt holes for accessory mounting.

 

[Joseph44]

Thanks Joe for the print, now let me ask you if it is a Pontiac motor will the cereal number be at the same place but the numbers are different. I would think if both motors are made by G M would not the holes for a/c comp. be the same? Thanks Joe you came through again. Have good day!!

[joe_padavano]

18 hours ago, Joseph44 said:

Thanks Joe for the print, now let me ask you if it is a Pontiac motor will the cereal number be at the same place but the numbers are different. I would think if both motors are made by G M would not the holes for a/c comp. be the same? Thanks Joe you came through again. Have good day!!

 

No and no.  I am not a Pontiac expert, but I do know that the block castings are shaped differently and do not even have that "shelf" that the Olds block has.  And both motors were NOT "made by GM".  Unlike Ford and Chrysler, prior to the late 70s every GM division designed and built their own unique engine lines. This is one of the most important things that differentiated Chevy from Pontiac from Olds.  As I've said several times now, the motors are COMPLETELY different.  There is NOTHING in common.  They were designed by different engineering teams at different times.  As I've also said, Olds did not install any Pontiac sourced motors in 1976 Oldsmobile cars.  Is there any reason why you think your car DOESN'T have an Olds motor?  Have you lifted the hood and counted the bolts on one of the valve covers?  Olds = 10, Pontiac = 4

 

Or are you simply pushing this because you have found a billet bracket for a Pontiac and you REALLY REALLY want to bolt it in your car?