Delmont 88 PA

Well, I fitted Sanderson shorty headers on a big block '67 Delmont 88. This was possibly the worst vacation day of my life....

The old 425 is still in the car and I wanted to make the necessary modifications to get the headers to fit prior to painting the frame and installing the newly-rebuilt 455. What a pain in the rear. The passenger side was easy--had to heat the cross member and indent it a little--piece of cake. The driver side required the same cross member modification, adjustments ("adjustments" seems too tame a word for the violent method used) to the rear tube on the header. Shaving a little off a few bolts, lowering the steering box a !/4" or so, and raising the engine. The new motor mounts will have the mounting holes (the ones that the bolt goes through to the block) welded shut, drilled higher, and then drilled to give a 3/8" to 1/2" lift. This will probably require the use of a grade 5 or 8 hex head bolt to allow maximum lift.

Now it will be a circus act to bring the 2-1/2" or 3" pipe through the steering linkage and bend it back while maintaining enough ground clearance to make it over speed bumps. At least it won't be for another 2 or 3 weeks until I have to do this--have to finish the engine and rebuild the TH400. Thank God....

oldcutlass

I would like to see pictures. We all understand that it's a major undertaking to get those in there.

Delmont 88 PA

Will do; however, it will probably be a few weeks since I pulled the heads on the motor that is in the car and am reworking them now. They will go on the 455 that is in my basement. My father-in-law and me wanted to do the fit in prior to removing the 425 so, after the frame and engine compartment are painted, and the 455 is complete, there will (hopefully...) be no more banging, bending or welding....

Delmont 88 PA

Oh yeah, major undertaking is an understatement....

Delmont 88 PA

Since getting pictures that show the header installation in any detail is tough I drew a crude sketch showing what was done at the header to get them to fit (below).

1. Heated and peened in cross member to make room for the front header tubes.
2. Opened up the motor mount holes in the cross member to allow the engine to be moved forward 1/2". Had to change the fan spacer but everything else seemed fine. The trans mount is to the very front of the trans cross member. After assembly of the rest of the front end I'll make spacers to prevent the mounts from sliding if the bolts loosen a little.
3. Opened the mounting holes for the steering box to the limits of the crush tubes in the frame to allow the box to be dropped a little.
4. Used 3" adapters and 2-1/2" 90's that needed to be modified as shown below. This was a pain.

It might be easier to install later model 88 steering gear and linkage and use long tube headers.

Delmont 88 PA

Hopefully the image is visible now.

Delmont 88 PA

Sorry, had to attach it as a bmp rather than just pasting the image.

oldcutlass

Well no pic's, but I do feel for ya. Congrats sounds like you got it tho. BTW you may consider a torque rod to keep the engine from sliding back and fourth if things loosen up.

Kennybill

The factory S drivers side is now being repoped. When I was wanting duals I couldn't find an S manifold. I had a set of Toro exhaust manifolds. The looked like they would flow good. Pass-side was great as is fit. Dr's side was cut and rotated 180* and weld with Ni-rod. A little grinding and it fit. The inside is lined up great. Basically my version of a WZ exhaust but for the 1965/70 88/98's. Just another option. There is a set of Toro manifolds for sale in the parts section. Good luck, Ken toroexhaustandshifter002.jpg 3-14-2007-42.jpg

redoldsman

Aren't the Sanderson rear exit headers for a 350 only?

captjim

And they are 1 5/8" primaries, right? I had 2 sets, both worked fine on 350s.

citcapp

They make them for both the 350 and the 455. The 455's are 1-7/8" and the 350 header is 1-5/8"

The 350 has two styles middle and rear
the 455 is middle only

redoldsman

It is interesting to note that they list the 3 different types by Oldsmobile engine and the 350 rear exit by Oldsmobile vehicle only.

Here is the link: http://www.sandersonheaders.com/Oldsmobile/

captjim

the 0350 is the center dump street rod header and the 0351 is rear dump for cars,
http://www.sandersonheaders.com/Oldsmobile-350/

Delmont 88 PA

Unfortunately, the rear dump headers won't work on a '67 full size Olds since the steering box is in the way.

Stumpy

But will the shorty center dump work with custom built/bend pipe? I would love to put a set of headers on my Delmont 88 I'm doing. I failed to mention I have a 330 in this one, but thinking its the same bolt pattern as the 350? Could be way off base, but hope someone here can tell me.

citcapp

If i remember right the big body cars use the front and center motor mount holed in the block. If this is the case the center dump headers would work if the areas of the headers clear. If the car uses the center and rear motor mount holes then the header dump tube hits the motor mount and will not work

joe_padavano

That is correct. The 1964 (yes, the J88) to 1970 full size cars use the forward two motor mount holes in the block. Interestingly, the LH single exhaust manifold for these cars is a center dump.

Something I've always wondered about is the 1973-74 Omegas, which are also rear-steer and use the forward motor mount position. You CAN get headers for these cars. I wonder if they would also fit the 64-70 full size cars.

Delmont 88 PA

The Sanderson's are mid-exit and they dump behind the front crossmember and the drag link. I was so tight that I had to use 3" outlets from the header and weld a 2-1/2 piece to the front of the 3" piece, peen the back of the 3" piece and weld it. That was after reaming out the motor mount holes to allow the engine to sit about a 1/2" forward. It was really tough and the clearance is little. If I build another Olds with the rear steering box I'll probably relocate it....

I have been I'll for a few weeks but will try to get pictures next week.

turbobill

I went through this on my '68 Buick Wildcat 20 years ago. Had to purchase headers for the A body and modify to fit the rear steer B/C body.

Passenger side was pretty easy, relocate one header tube and trim one block register. Drivers side required major surgery. Three tubes had to be redesigned to clear the steering box. One tube had to go around the tie rod similar to the late 60's smaller Mopars with headers.

Overall, it took two weeks to accomplish including the 3" mandrel bend exhaust (hand fabricated) to the mufflers. Nothing on the car itself was altered or modified. Other than the block register, all modification was done to the headers.

Now and then, someone will notice the car has headers instead of the exhaust manifolds. I even retained the hot air stove to the air cleaner.