So its my first time installing headers. I bought some flowtech headers from oreilly auto parts so im not even sure if there going to fit. With some elbow grease i was able to get the manifolds out. do i have to pull the engine entirely to get the manifold in or did i get the wrong headers?

 

What part # are the headers and what are they going on? Are you putting them in from the bottom? Did you remove the oil filter and adapter on the pass side and the starter on the drivers?

 

As the previous poster said they need to go in from the bottom. You don't have to remove the engine, just lift it a bit. Jack the front of the car as high as you can get it and support the frame just behind the front tires with jack stands.

 

It's on a 72 cutlass s with a bone stock 350. The only thing I removed were some lines that go from the radiator to the trans. The part number is FLT 11150

 

You have the correct headers. The oil filter and adapter will need to come off. No big deal 3 bolts and a new gasket. On the drivers side the starter will have to come off.

 

Take them back and just setup a true dual exhaust. This eliminates removing filters, lifting engine and possibly breaking oil dipstick tubes. It's ridiculous to have to remove filters, tubes, lift engine etc... for some headers on an Olds. I ended up buying the Pypes downpipes and simple pipe extensions at CAP auto with some 2.5 turbo mufflers. Sounds much better and I'm sure it was worth the 3 hp on my 350 2 barrel. Caution! you will need an exhaust donut for the drivers side exhaust manifold to seal properly to the Pypes system. Pypes are 2.5" and the drivers side manifold is 2.25".

If you need part #'s let me know

 

They can be installed from the top, doing one side at a time remove the motor mount bolt and raise the engine on that side- I personally have never had to remove the starter or the oil filter- drop the header in, attach loosely with 2 bolts, lower the engine, replace the motor mount bolt and move to the other side. Pain in the *** somewhat but it is not that bad of a job. Good luck.

 

From the bottom is really easy. To me, removing the oil adaptor and starter is no big deal. Maybe 20 minutes. Oh and yes the dipstick tube. Very easy to remove. Just clamp easy on it and tap it out. Not a problem. JMO

 

If you can install from the top by raising one side of the motor at a time,
Then can you attach the headers to a motor that's hanging on a hoist and slide the whole works in place?

George

 

Are you talking shorty headers or full length? I can imagine installing the drivers side from the top. I have never installed a set but looking at my 72 Cutlass I don't see how.

 

I got hookers on my 70 and I install them from the bottom. Had to lift the engine couple of inches to clear driver side. I can tell you one thing it's a PIA to get them in. Also I added few inches of rubber hose to the tranny cooling lines to clear the headers. There is some issues with fitment of Flowtech headers, you might have to "modify" them with the hammer a little to get them in.
If I had to do it all over I would go with shorties.

 

I have a 72 S. The install was from the bottom. We put the front end up on jacks as high as we could to get them up from the bottom. Eric has it right with removing the oil filter and starter. Also you may have to manipulate one of the tranny lines, it's almost touching the header on passenger side on mine.

What also helped was using the floor jack to rest the header on once it was maneuvered up from the bottom, especially when bolting on so the weight of the header doesn't leave gaps. The toughest bolt to tighten will be the one on the back of the driver side because of the steering column, but using the jack to relieve the tension was the trick to getting it tight.

My A/C is removed a long time ago so not sure if there's access issues if it's there on the passenger side....good luck.

 

Don't forget to move the brake proportioning block from the driver's side frame rail to the top of the rail. If you don't, you run the risk of having the brake fluid boil and no brakes! Wanna ask how I know this?

 

I've gotten into a couple of 70-72 350 installs that had to take the trans cooler lines loose and route those thru the passenger side header. That or would have had to cut them and run rubber hose like 70cutty described.

I think shorties are the best option on street driven cars too. 'Course back when we were doing those cars, there warn't no Oldsmobile shorty headers.