88jetstar

Hello,
I have a 64 jetstar with a 330. My exhaust manifolds are cracked where they bolt to the heads. I would also like to run true dual exhaust. Will these manifolds work on my car?
http://www.opgi.com/cutlass/1964/exh...folds/C240688/

I am open to all ideas and if there are headers that would fit i would love more details on them.

Thank you

tru-blue 442

Those might work just fine.
But you can go to Thorton's
website, and can save a few bucks.
I think they sell them for $299 + ship

okie88

I'm pretty sure those won't work on your Jetstar. Your steering box is in the way of those rear dump manifolds. I just had duals put on mine. We had to run the crossover style pipe, and both exhaust exit on the passenger side. The crossover is behind the transmission, and the way the exhaust dump in the back is opposite of the front. It was a full day job for the pipe benders, but your steering linkage and box really complicate the job.

okie88

I should have specified the driver side is the one that won't work.

sixtyfour

Try checking out the Thorton headers. I bought a new set for my 1964 Cutlass that has the 330.

88jetstar

http://thorntonmusclecars.com/produc...aust-manifolds

if the manifolds in the link are the same as what you guys are talking about they look just like the opgi ones just a bit cheaper, which i am always a fan of, still not sure how to clear the steering box, there looks like there is room, i may have to get creative.

has anyone used one of the DYI header kits?

sixtyfour

I'm pretty sure their the same ones, When I bought them I couldn't find any tublar type headers that would fit, so the Thornton were the only choice. I do remember that the guys at Thornton said they were sized internally for the 455 but were casted to fit the 330 and 350 heads, so I liked the fact I was getting increased flow. I think I paid about $420 bucks or so, could be wrong. But quality seem good, no problems with install

joe_padavano

I'll suggest that you actually compare these SBO manifolds to real BBO W/Z manifolds. The SBO manifolds are physically smaller, so I'm struggling with the concept that they are "sized internally for the 455". There just isn't room due to the SBO's shorter deck height, which is why real W/Z manifolds can't be used on an SBO. And please note that I am not bashing Thorntons, just pointing out a flaw in logic.

88jetstar

anything has to be better than the 50 year old broken ones i have lol

steverw

If you Zoom the OPGI ones you can see that it says Thornton on it.

sixtyfour

Yeah Joe, I agree with everthing you have stated. Thorton at the end of the day are trying to sell you stuff so the internal size stuff probably just sales chat. All I know is they went in with very little effort and the clearances were as good as the orginal, so.......... when you got nothin, it's always good to have something working. Not sure how the Jetstar will be

lunaboy

I have an oem drivers side from a 66 88 jetstar if you want to go single to duals

88jetstar

do you have the driver side and passenger side? i need both if i am going to do that

jag1886

The Thornton manifolds are larger than the stock manifolds, they still fit as well as the stock ones and have larger outlets for the exhaust pipes, I have had the 2 on the floor side by side so this isn't an opinion it is a fact.
I have no idea what a W/Z manifold looks like but the SB Thorntons are styled after the BB manifolds, they many not be as big as a BB manifold but are larger than stock SB manifolds.
I think they helped the performance of my mild mannered car if for no other reason than I can get a larger head pipe on the engine. I think they where worth the investment, buy them direct from Thornton and save the money.

88jetstar

Does anyone know how long thorton takes to respond to an email? I tried calling and it seems the number is no longer in service

sixtyfour

Usually right away, plus I think I called them on the phone and they answered. Might be out for a day or two on a trip or something

88jetstar

weird I emailed them Tuesday

rennoc442

I know this is an old thread but did you ever finish this project?

wr1970

Yes for a old thread i am surprised no said to have them welded in a furnace! Much cheaper than buying a new set of manifolds.JMO

88jetstar

My life has been hectic ever since this thread. I still have the manifolds but I have not been able to test them. My living situation is fairly fuild. However I am in escrow now and hopefully when I move I can get some time with the car.

88jetstar

Oldstata helped me out with a set of manifold from a mid 70s small block a while ago. The driver side and cross over do not clear the steering knuckle on the driver side. The passenger side manifold appears to be exactly the same even though the casting numbers are not the same. This is a big help as my passenger side manifold looks like the grand canyon.

olds 307 and 403

Are the motor mounts on the front or mid engine?

joe_padavano

The 64 J88 uses side motor mounts that bolt to the front two of the three bolt holes in the side of the 330 block, just like the 65-70 full size cars. That's because the 64 J88 is rear steer, like those 65-70 cars.

olds 307 and 403

Depending on the steering set up, center dump Sanderson headers might fit.

88jetstar

Do you have link to those headers?

olds 307 and 403

http://www.sandersonheaders.com/sand...category_id=41
I had these in the Olds powered 4x4 but due to it being a 4x4, proper exhaust was too tight to route. It used the front holes also, sold them to a guy planning on a turbo project.

88jetstar

Thank you, they look like they would fit. There is only the photo on their website. I emailed them asking for more. If I stay with the stock motor those would be great. The idea is to stay with the stock block as long as there are no cracks in the block or heads.

olds 307 and 403

They fit tight to the block and come with the angle collectors. Summit also now carries them.

RAMBOW

Since this is rear steer like the later b-bodys... wouldn't this be what you'd need?

http://thorntonmusclecars.com/produc...aust-manifolds

THen you can just run whatever on the pass side since they all clear. It was the drivers side that had the issues.

(sorry if i'm mis speaking... I had a 68 Delmont that had this problem back in the day, wished this part had been available back then!)

DropTopVic

I just replaced the factory exhaust manifolds (mine were modified for dual exhaust), Intake manifold, Starter, alternator, and valve covers on my 67 cutlass supreme convertible . I am In NC. They are all for sale if you need them.

BangScreech4-4-2

OP has probably found what he needed or abandoned the project altogether, as this thread is over seven years old and he's only been heard from once in the last five. Otherwise, I'm sure he would appreciate your offer.

joe_padavano

Well, that and the fact that Jetstar 88s used different manifolds than did A-body cars.

BangScreech4-4-2

As was established earlier in the thread, so ... yeah.