Switching from 350 to 455

shopaholic07 · March 4th, 2009, 09:01 PM

Will the existing manifolds work when switching fro the rocket to a 455 or will they have to be changed?

J-(Chicago) · March 4th, 2009, 10:01 PM

intake manifold will not swap over.
exhaust manifolds will.

64Rocket · March 4th, 2009, 10:07 PM

Yes, they will fit, if you have single exhaust you will have to rework the crossover.
The main thing is they are much smaller and restrictive. If you have dual exhaust you will have some align problems.
Gene

70_Convert · August 2nd, 2009, 07:05 PM

I replaced the 350 Rocket in my 70 convertible with a 455, 68 police intercepter kit, headers. Dropped right in.

citcapp · August 3rd, 2009, 09:03 AM

Don't use the 350 exhaust manifolds on the 455 way to small and restrictive. Use headers of W & Z headers. You can find them on e-bay

joe_padavano · August 4th, 2009, 09:19 AM

While they will physically bolt up, in addition to being overly restrictive, the other reason not to use SBO manifolds on a BBO is that the exhaust flanges are in different locations. The BBO manifolds (at least on the A-body installations) are designed so that the exhaust flange is at the same location as it is on the SBO. Using the shorter SBO manifolds on a BBO will put the flanges higher and further outboard, which makes custom pipes mandatory.

March 4th, 2009, 09:01 PM	#1 (permalink)
shopaholic07 New User Join Date: Jan 2008 Posts: 4	Switching from 350 to 455 Will the existing manifolds work when switching fro the rocket to a 455 or will they have to be changed?

March 4th, 2009, 10:01 PM	#2 (permalink)
J-(Chicago) Seasoned beater pilot. Join Date: Jan 2007 Location: Chicago Posts: 2,697	intake manifold will not swap over. exhaust manifolds will. __________________ I'd rather have a numbers matching poker hand.

March 4th, 2009, 10:07 PM	#3 (permalink)
64Rocket Registered User Join Date: Sep 2006 Location: Union City Calif.94587 Posts: 301	Yes, they will fit, if you have single exhaust you will have to rework the crossover. The main thing is they are much smaller and restrictive. If you have dual exhaust you will have some align problems. Gene __________________

August 3rd, 2009, 09:03 AM	#5 (permalink)
citcapp Super Moderator Join Date: Nov 2007 Location: Bothell, WA Posts: 3,455	Don't use the 350 exhaust manifolds on the 455 way to small and restrictive. Use headers of W & Z headers. You can find them on e-bay __________________ Pat 1957 Super 88 with a 455 1948 2dr series 76 with a 455

August 4th, 2009, 09:19 AM	#6 (permalink)
joe_padavano Super Moderator Join Date: Mar 2007 Location: Northern VA Posts: 4,402	While they will physically bolt up, in addition to being overly restrictive, the other reason not to use SBO manifolds on a BBO is that the exhaust flanges are in different locations. The BBO manifolds (at least on the A-body installations) are designed so that the exhaust flange is at the same location as it is on the SBO. Using the shorter SBO manifolds on a BBO will put the flanges higher and further outboard, which makes custom pipes mandatory. __________________ Joe Padavano 64 Jetstar 88 Conv 66 442 L-69 Conv 68 W-30 69 H/O 69 442 70 W-30 72 442 84 Custom Cruiser 86 Caprice wagon (w/307 Olds)

August 2nd, 2009, 07:05 PM	#4 (permalink)
70_Convert Registered User Join Date: Jun 2009 Posts: 6	I replaced the 350 Rocket in my 70 convertible with a 455, 68 police intercepter kit, headers. Dropped right in.

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