Rocket73

I have a set of flowtec headers for my 73 cutlass 350. They are not suppose to fit my car because its a floor shift auto. I called the company they said it has something to do wit the linkage. They weren't very helpful. Anyone know what the issue is and if I can make these headers fit.

Allan R

Not the answer to your question, but why would you buy a set of headers that are not supposed to fit your car?

I suspect it has something to do with where the back drive linkages and equalizer bolt up, but not 100% sure.

Smitty275

I bet they go right on with out issue.

Rocket73

I didn't buy them they were given to me.

oldsfromyell

Listen to Smitty not the other guy and you will be fine.

Allan R

Only way to find out is dry fit them. This sounds a lot like the argument from some of the aftermarket exhaust company's saying that the 70-72 Cutlass Supreme can't use the same headers as for the f85/Cutlass. They fit both just fine since the engine and trans are mounted in the same place.

Rocket 73 - good deal! Hope it all works out.

joe_padavano

Well, if they don't clear a floor shift AT, they won't clear a column shift AT, nor the clutch linkage of a manual trans, so that means they wouldn't fit any car at all.

As noted, the issue is the backdrive linkage that locks the shifter with the key. At worst, you can rebend the backdrive rod to clear.

aretubj

The fitting has to do with the shifter linkage.
The linkage from the frame to the tranny is different on floor shift and column shift cars.
It's an easy fix, just a matter of bendind the rod.
Some of the header manufactures post the fix on line as part of their installation instructions
Joe

Rocket73

Thanks for the info. I'll post my results when I do the job, hopefully no problems.

Doug Blake

Did the exact same thing couple years ago. With new ceramic coated flowtech's in 73 Supreme with floor shift. You have to remove the lower frame braces and oil filter adapter, then hammer the drivers tube that's straight down flat so it's "D" shaped for against the firewall. Very close to the brake proportioning valve too.

MSRA #9615
NAOC #4962
OCA #023589
1954 98 Holiday Deluxe HT
1973 GMC Sierra 3/4-Ton Tow Truck
1972 442
1973 442
1977 442's (2)
1983 Hurst/Olds T-Tops #1536
1985 442
1986 Cutlass Supreme Brougham
1989 Cutlass Supreme International

73supreme

I only use Hooker headers on my 1973's. They claim they don't fit the Supreme. Why that app would be different than an "S" is beyond me. I have done both 350's & 455's, with different trans. I had to remove a bolt- on diagonal brace tube to the frame, also had to reroute the brake line to avoid contact, trim an A-arm bushing ear and dent a tube to clear frame, be sure to use the starter heat shield and watch the battery cable location, but otherwise a PERFECT fit!!!!