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As the title says, I'm looking for a RH exhaust manifold for my 455 rebuild. Mine is cracked and can't be fixed. I'm not too concerned about pitting but I don't want any cracks. I've attached a pic of mine for reference. Thanks.
i didn't know that. the motor was transplanted into a '79 trans am and the guy i bought the car from told me it was a 455. i've tried to look up block #'s, etc. but have been a bit confused by them. maybe i have a 350 but i've been rebuilding it on the assumption it's a 455. i'm pretty new to this.
i didn't know that. the motor was transplanted into a '79 trans am and the guy i bought the car from told me it was a 455. i've tried to look up block #'s, etc. but have been a bit confused by them. maybe i have a 350 but i've been rebuilding it on the assumption it's a 455. i'm pretty new to this.
First, what is the block casting number above the water pump?
Second, SBO manifolds will bolt to a BBO and vice versa. Of course, the SBO manifolds are more restrictive and will negate some of the benefits of the engine swap.
Third, whoever did the engine swap likely just reused the original 403 manifolds, which is probably what these are. Since the 455 was never installed in the F-body, 455 manifolds may not work anyway. Would have been helpful to know we were talking about an F-body installation to start with.
i have a pair of 455 mani's they are still on the motor..i drove the car before i took it apart...if ya want a pair..let me know and i can get some pics etc..i have to pull them...
the original motor, which i have, was the Pontiac 301
thanks for your help
Yes, that's a 455 Olds block. The manifolds must have come from some other application. If you do use BBO manifolds, they will put the exhaust flanges in different places and will likely require different pipe routing.
....if i use the 350's they'll fit to the stock exhaust w/o modification.
What Joe was saying is the manifolds will physically bolt onto the engine; however, the 455 is wider than the 350 and you may have clearance issues. FWIW, I installed a 455 into a Firebird, using Cutlass headers, if you want to go that route.
What Joe was saying is the manifolds will physically bolt onto the engine; however, the 455 is wider than the 350 and you may have clearance issues. FWIW, I installed a 455 into a Firebird, using Cutlass headers, if you want to go that route.
What I'm also saying is that OP hasn't provided enough info.
Had this 455 been previously installed in this F-body before you got it, with these manifolds and exhaust routed or not? If it has, they using "correct" 455 manifolds will require fabrication of new pipes. Using the "incorrect" SBO manifolds will mate to the existing, custom-bent plumbing.
If this is a 455 that you obtained to swap into this car (which came with a 301 Pontiac), then any exhaust piping is new and I'd get 455 manifolds if they fit in the chassis.
ok. so i think i lost the reply i just tried posting. i'll try again.
sorry for not being clear.
the 455 was already transplanted into the TA and mated to the stock exhaust with the 350 manifolds.
as much as i'd love the better performance of the bbo manifolds, i think im going to have to use the sbo's with an out-of-the-box, stock-bent exhaust system to save some $. the longer the resto goes on the harder the budget gets hit.
i do appreciate all the input. i'm learning a lot but have so much more to learn.
I understand the incremental cash flow issues. This is one of those areas that can be good enough for now and upgraded later when funds are available. If you plan to mate to the existing pipes, you should post the casting number of the manifold you are looking for to ensure an exact duplicate. The number is not completely legible in your photo and there are some year-to-year flange angle differences.
Also, I doubt stock pipes would mate to SBO manifolds on a BBO without some tweaking. The BBO's taller deck height pushes thos exhaust manifolds (and thus the outlet flanges) about an inch higher in the car. You might get lucky, but you might need to lengthen the down pipes to accommodate this. I assume you are running dual exhausts and capping the crossover port? The stock SBO crossover pipe will definitely not fit with these manifolds on a BBO unless you modify it.
thanks joe. it's a lot to consider. i don't recall any mods to the original down pipes when i removed everything but that was several years ago and they're long gone.
