mgue67

I have read many posting regarding headers for a 1970 cutlass supreme convertible. I have been working on my olds for the post year and finally beginning to reassemble – pic’s to come. This weekend I installed the motor and a set of hooker headers. Both the website and the technical line for hooker said they would not fit but as posted - wrong. The header went on without a problem. It took less than thirty minutes without the need for a big hammer, cutting or modifying.
Thanks to those who have posted in the past. Without your input I would have passed on the install.

scott71

Can you get me the specifics as to what header those are? I am looking for some for my 71 cutlass supreme. I am having a hard time finding any. Also are they a full length header? I have a set of hedmans on there now that hang to low and it needs to be fixed, so i'm looking for a nice high and tight set up. If i need to get a new starter to do so I will. Do you have a high torque low pro starter or not? Thanks for any help you can give me. Scott

2blu442

Scott, any headers that will fit the Cutlass S or 442 models will fit the Supreme. There have been several threads discussing the bad information out there including from the dealers who sell them. I've had a couple different brands and they all seem to hang down lower than the crossmember. John

joe_padavano

All Olds full length headers that I've ever seen will hang below the crossmember. That's the price you pay for proper equal length primary tubes.

Bayou Olds

Happy for you. I just dropped my rebuilt 350 in my 70 convertible. My new Flowtech coated headers slid right into place, but the motor mount rubber is contacting. I have the motor mounts out now and will be grinding rubber this evening.

scott71

can you give me the specifics of the hooker headers used? Model and maybe were you purchased them from. Thanks a lot

Scott

Bayou Olds

I used Flowtech 31150FLT headers. I got them through Summit Racing. I think I paid $275-$279. They are $285 right now.

https://classicoldsmobile.com/forums...-img-9203.html

The link is a picture of the headers before I ground the rubber and tightened.

mjrocketride350

I tried the flowtech 11150flt headers and they did not fit. They don't fit if you have an automatic transmission. Obviously you people don't have a clue what you're talking about.

oldcutlass

I'm assuming your car is a 70. What issues are you having or are you going by the application data?

mjrocketride350

They won't fit past the transmission. My brother in law who is a mechanic said they would not fit in properly because the transmission is too wide for them.

oldcutlass

Which transmission is in it and is it a 70?

mjrocketride350

It's a 70 with a turbo 350.

oldcutlass

It should not be hitting the transmission, have you called flowtech? There are conflicting applications on the Summit site for them. By all means they should work.

joe_padavano

Well, in that case, they won't fit any other Cutlass, Supreme or not.

One more time: There is NO DIFFERENCE WHATSOEVER in the frame, trans, engine or location of a Cutlass Supreme and the same year Cutlass. The only difference is the rear roofline, and if that causes a problem for your header installation, you're doing something wrong. Summit is clueless. Assuming your car has the original TH350, that trans is EXACTLY the same width as every other TH350 ever made.

Might the problem be the backdrive linkage, and not the actual transmission?

Feel free to post photos of your "too wide" transmission. Others here will post photos of their Cutlass Supremes with headers installed.

Fun71

The only thing I see on the application notes is that these headers will not fit auto trans with column shift. This would be due to interference with the backdrive linkage as Joe mentioned above, but even that doesn't make much sense to me as the floor shift cars have the backdrive linkage for the ignition lock feature. As for as I know, the backdrive linkage is the same between floor shift and column shift cars, but I have never owned a column shift cat so I am just going by what I have read on the net.

Octania

To me, that means "does not fit" translates to "requires more effort to work around and still have all the features you had before". Such as, gear selection via steering column, or backdrive to the column to run locking, neutral safety, backup light switch, etc.

The frame is the same
The body in this area is the same
the engine and trans are the same

There is NO reason that anything that fits a Cutlass or 442 will not fit a Cutlass Supreme.

It is the second greatest Olds Myth right after the Solid Main Web 403.

Kill it.

Fun71

Chris, I agree with you. My point was how can it fit a floor shift car but not fit a column shift car if both cars have the same backdrive linkage?

Anyway, I have a set of Heddman headers on my car and they do not interfere with the backdrive linkage.

Eric Anderson

Speaking from past experience hooker 3901hkr headers for a small block fit with no modification to anything. The only thing I can say about them is the drivers side might be tight at the lower control arm area. The 3902hkr for big blocks require the shift linkage rod to be flipped and a little bend/ twist to be put in it. This is on 70-72 a body.

joe_padavano

Because on a floor shift car, you can remove the backdrive linkage and still drive the car.

And as Chris noted, the backdrive linkage can be bent to clear. It just isn't a complete bolt-in operation. Header manufacturers don't know the skill of the installer and tend to err on the side of conservatism. Of course, as noted above, SOME manufacturers can actually route the pipes to clear anyway. Go figure.

oldcutlass

Yeah, but if you look at the different years for application, the notes make no sense. At least on the Summit site. There is no difference between the 31150FLT and the 11150FLT headers other than the coating. Yet the applications are different and conflicting.

Townie

I installed a set of stainless headers on my 72 Supreme with auto floor shift, they are Pro Comp part# PC5035. It was a very frustrating job I had to try 3 different brand mini starters because of fit issues and the passenger side hangs really low so I have to be extra careful when pulling in anywhere. If I have to do it again I'll buy those W & X repro 350 manifolds.

joe_padavano

Again, these problems are not unique to the Supreme.

And just so we're all on the same page, ALL full length headers hang lower than stock manifolds. It's not possible to get equal length tubes any other way. Either one is willing to put up with the compromises to get the performance, or one should stick to stock manifolds. And I would suggest closely comparing aftermarket SBO manifolds to stock before plunking down $300. Your money, your choice.

Townie

You're right Joe when we talk about headers we should just put Cutlass because there is no difference, I think it is the way they advertise them when you do a search. I read somewhere the factory used a block off plate on the cross over to run dual exhaust? I just can't wait to start cruising.

joe_padavano

Correct. There were never factory "dual exhaust manifolds" for the SBOs. Even the W-31s got the cap on the passenger side manifold.

olds 307 and 403

Flowtech are a poor header. I had ceramic peel and rust pin holes everywhere after a year. They were A body headers in a 1/2 ton. Hedman and Sanderson make Shorty headers for those years.

70vert

Flow tech headers fit just fine on my 70 cutlass convertible. They are a little close to the shifter cable but nothing to get in a twist about. Also have ample clearance around the back drive linkage too.

Bayou Olds

.
Before you make disparaging remarks look at the posts. I have been running the same Flotech headers for about 4 years with ZERO issues, that is other than tightening header bolts, but that is expected. I think your issue is address in a response above "requires more effort to work around", than you or your "mechanic" brother in law wants to put in. I have not posted here in a while, but this place can be a wealth of knowledge for those who want to listen. BTW that is a Cutlass Supreme I drive that appears in my profile pic. Again ZERO issues for 4 years..............

joe_padavano

He hasn't been back here since March 28. Don't waste your time.