I have a 289 in my 67 right now but I have been toying with the idea of swapping it out for a 357W with AFR 185 heads. My question is will my JBA 1 5/8 shorty headers fit? I know the bolt pattern is the same but every time I see someone post about swapping to a 351 they are always told they will have to change headers, why? I would like to hang on to the JBA's as they have been a good header and I also have clearance issues with my custom rack and pinion. Thanks for your help.
Headers for 351W
- Thread starter 67chad
- Start date
headers
The reason why most 289/302 headers will not work with the 351 is that the deck height is different and most 289/302 headers will not clear the floor support. If the crate motor you are planning on putting in is based on 289/302 your headers should fit. If the crate motor is based on the 351, then they may not fit if they are long headers. Shorties should fit for both although most 351 shorties have bigger primaries. I am running headman shorty 351 conversion headers on my '68. They fit pretty good.
The reason why most 289/302 headers will not work with the 351 is that the deck height is different and most 289/302 headers will not clear the floor support. If the crate motor you are planning on putting in is based on 289/302 your headers should fit. If the crate motor is based on the 351, then they may not fit if they are long headers. Shorties should fit for both although most 351 shorties have bigger primaries. I am running headman shorty 351 conversion headers on my '68. They fit pretty good.
65ShelbyClone
Founding Member
I have a worn out 351W sitting on a stand that I'm thinking real hard about building into a nasty 393. My goal would be 500fwhp/420rwhp if I bother at all.
If you're just after 400hp, you could go either way on the header size. 1 5/8" will make more lower-rpm torque which is actually more useful on a street car(as opposed to 1 3/4"). Shorty headers are not usually an issue with Windsors. Longtubes for 289/302s have trouble being used on 351Ws because the collectors will hit the floor under the car due to the taller deck. If your shorties have at least 1 5/8" tubes, you could reuse them and just get the exhaust downtubes lengthened.
67chad said:
If you're just after 400hp, you could go either way on the header size. 1 5/8" will make more lower-rpm torque which is actually more useful on a street car(as opposed to 1 3/4"). Shorty headers are not usually an issue with Windsors. Longtubes for 289/302s have trouble being used on 351Ws because the collectors will hit the floor under the car due to the taller deck. If your shorties have at least 1 5/8" tubes, you could reuse them and just get the exhaust downtubes lengthened.
65ShelbyClone
Founding Member
I forgot to mention that shorties also free up some space for (stock) power steering and stock clutch linkages. I have longtubes on my '68/302 and the z-bar goes between some of the primaries. I have to pull the z-bar to get the header out.
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