70cutty

For my new 455 build I bought Doug's headers, 1 7/8 primaries with 3.5" collector. Over the weekend I was trying to put them in the car, after fiddling with them for about 8-9 hours, finally they were in place. I thought I share this with CO so nobody wastes their money and time on these.

Problem areas
Driver side - one of the tubes is on the frame, no gap between.



I figured screw it, I can dimple it a little and make it fit. Before doing that I tried installing passenger side.

Passneger side - one of the tubes is on the frame


Passenger side collector is about 2" higher than driver side so it hits the floor board.





Since I bought these back in February and had them shipped to Mark for the engine to be dynoed with them, I feel like this is gonna be a long fight.
I can almost see my $730 gong down the drain.
I am gonna call Doug's today and see what they say.
Should have bought ARH.

70cutty

So I just got of the phone with their tech. He said something is out of spec., they sent me the shipping tag to ship them back to them. I wonder how long is this gonna take.

442Harv

What year car is it? I have a 70 4SP car and they fit good, also had a 70 Auto, and they fit fine. I agree that there is something wrong, with the headers, and need to go back.

70cutty

It's for my 1970 Cutlass S with a 455. Are yours headers BBO headers? The ones I got are 1 7/8 with 3 1/2" collector.

BlackGold

Before you blame the headers, are you sure you have the right motor mounts, properly matched to the frame mount and engine combination? Also, are you sure you ordered the right headers (455 vs. 350)?

70cutty

At first I was hoping it was just user error.
I am using 350 mounts since my car is originally 350. I am sure they are the right headers, I haven't heard of anybody making 1 7/8 and 3 1/2" collector for SBO.
My little hookers that were on 350, look puny compare to these.
They don't fit in different places and when you look under the car driver side collector looks fine, passenger side is 2" higher and it's hitting the floor.

It's the headers.

oldstata

I am not sure on a 70 but I know the early cars 64,65 use the small block mounts with the big block, but I seem to think that the later years had different mounts for the Bbo might want to check into this even tho you might still have header issues
Joe P thread

You might have to cut and paste as co currently don't like I phones

https://classicoldsmobile.com/forums/tech-editors-desk/33826-motor-mount-application-list.html

70cutty

I triple checked everything. Engine mounts 2261 for small block since my car was 350.

Driver side. Plenty of room between the floor and collector, it clears the cross member and it sits in the right location.


Passenger side hits the floor, doesn't clear the cross member and it sits crooked, outwards.

geoff442

Hi.I just tried putting a set in my 71 442 455 engine, I had the same exact problem with the left side header. I put new motor mounts in before I put the headers in, same fit as in your pictures. I never even tried the R/side put them back in the box to send them back. The headers were a nice set very well made, but I was disappointed they didn't fit.

70cutty

According to Doug's the headers have a design flaw, especially on passenger side. No S**T. They are working on getting a car to re-design the headers.

If anybody is trying to buy these - DONT. This goes for the 1 7/8 primary with 3.5" collector. Part # D743.