[formula kid]

Looking for SD 455 intake manifold #485640.

[Joe's Garage]

Pete McCarthy's book is in error where it lists the 485640 as the 'non production/experimental' SD455 program intake.

While it may have been designed, and the part number assigned, during the engineering and development of the SD455, there is no evidence that any were ever installed on SD455 engines for production vehicles.

By the time the SD455 program was given the go-ahead, the emission requirements neccesitated an EGR valve on the engine. The 485640 has no provision for that EGR valve. That's why Pontiac designed the LSX2 intake.

With that said, if you are still looking for one, I think we have a couple. I'll PM you after I verify.

[Tellyshavilli]

Originally Posted by Joe's Garage

Pete McCarthy's book is in error where it lists the 485640 as the 'non production/experimental' SD455 program intake.

While it may have been designed, and the part number assigned, during the engineering and development of the SD455, there is no evidence that any were ever installed on SD455 engines for production vehicles.

By the time the SD455 program was given the go-ahead, the emission requirements neccesitated an EGR valve on the engine. The 485640 has no provision for that EGR valve. That's why Pontiac designed the LSX2 intake.

With that said, if you are still looking for one, I think we have a couple. I'll PM you after I verify.

Good explanation

[formula kid]

Thank you but I do have the 72 intake manifold #488945. This part is like the All Alum Block that was sent to Nunzi for testing.
People say that there was no such thing but he told me he had one.

[Tellyshavilli]

Originally Posted by formula kid

Thank you but I do have the 72 intake manifold #488945. This part is like the All Alum Block that was sent to Nunzi for testing.
People say that there was no such thing but he told me he had one.

485640 Is later 72HO intake superseded part number and there are many of them out there I’ve had at least 15 to 20 myself nothing special. Absolutely not a Super Duty intake manifold but will work good on one

[sd7369]

BTW, it is not out of the realm for an original cast iron 73 SD intake to be in the $4-5,000.00 range. If you can find one for less buy it. It may be a very long time until find another.

[LATRLL1]

I have a 640 intake with the correct crossover and heat shields.....PM me if you interested