I have 65 olds dynamic 88 w/ 425 motor. i am thinking of putting a new exhaust system on this next summer. My ehhaust manifolds are in bad shape. some of the studs are broke off (had to drill them out and use bolts w/ nuts) the manifold on the left side one stud has most of the threads stripped off. any idea what i should do? did not know if i should be looking into headers or what. a nice set of manifolds seem to be hard to come by unless someone knows of where a place is making them. thanks chris

 

I thought all of the Olds exhaust manifolds used bolts not studs. The easiest way to fix it is to remove the old, pitted hardware and replace it with new, grade 8 bolts from the hardware store. Make sure you use anti-sieze on the bolts when you install them.

 

The best way to fix a bad threaded hole is to have a helicoil or similar thread repair insert installed.

 

the studs for the cross over pipe appear to be part of the manifold. those are the ones im having the most trouble with. had one set break off had to drill them out and use bolts, nuts and washers, but the cross over pipe does not line up real well. the main exhaust pipe coming up to the right manifold is threaded and just bolts in but the cross over has studs. chris

 

If you get hard up I have 1 330 manifold and 1 350 manifold laying around. I had them on my 72 delta's 455 for a little while and they worked ok for beating around to school and work.

 

thanks j i will keep that in mind. chris

 

The '65 88 ,425 left side manifold is one that dumps in the middle. As the power steer box is behind. So the left side manifold is somewhat "Y" shape and the cross over goes in front of the pan sump and over to the right side. Using the bolt and washer and nut should be fine, just have an exhaust shop make another crossover for you. Better yet have them fab you a dual exhaust sys.

Gene

 

If you get a shop to fabricate dual exhaust around your steering box then have the front of your passenger side manifold welded closed. It looks bad and has a tendancy to leak if they just pinch the pipe and weld it up.

 

i was thinking of doing something like that. i saw on ebay a company as the left side manifolds as a reproduction that i could turn it into duals. they want a 170.00 for it. but it would solve my problem. i dont know have to see. thanks for the advise. chris

 

go to thorton reproductions....google search for the link or search for the link on this site. i have a pair of the repro duals for my 66. they are perfect and not that expensive...certainly cheaper than a custom set of headers or the factory manifolds. they are close to exact repros and bolt right on. paint them up in some vht high heat paint (follow the baking directions to the t..otherwise the paint will burn off) and you will be good to go. i spent over 10 years looking for a set of dual exhaust manifolds for my 66 and im glad i waited for someone to repro them. i suggest using fel-pro exaust gaskets on them even though the factory doesnt suggest them. these are really the only way to go anyways...i dont imagine a custom set of header wrapped around that steering box on the left side are going to get you anymore performance. just watch when you run that left pipe and make sure its not to close to the starter...i wrapped my starter and have no problems overheating it. hope this helps

 

I'm a new member but I thought I would try putting in my 2 cents worth. When running the left side pipe for duals, keep in mind that the shifter linkage from the frame to the trans has to be modified if you don't have one of the original arched ones.

 

Headers are not made for these cars because they are a rear steer car, in which the steering components are behind the axle making it really difficult to fit headers on the car.

 

First gen Camaros are also rear steer, and there might be one or two sets of headers made for those cars...

Same for the 65-70 Impala/Caprice.

There are no common headers made for the 65-70 Olds full size because they are not popular and the demand won't justify the development cost. Kooks may make a set, but the mainstream header manufacturers do not.