Doug's Headers & Oil Filter
 

Some people have had issues with Doug's Headers and not having room for the full size filter. I just installed my 1-7/8 round port Doug's and have plenty of room for the full size filter. Just an FYI

By the way these headers are a work of art. I paid the extra dollars for the ceramic coating and I love them.

i bought a set of those for my sons car...i wondered if they fit as good as they look. his is still on the shelf until he gets back home

I really like my dougs headers as well, great pieces. However on my first gen Bird, there is not enough room to get a full size oil filter in place. I use an LS sized wix and do my oil changes more frequently.

In my experience the issue of getting a full-size filter in there with Doug's headers only occurs with a stock manual transmission bellhousing. I've had to cut off part of it on the passenger side for clearance in the past. Automatic transmissions don't seem to have an issue.

That is plenty of clearance. Looks like you might be able to fit a WIX 51049 which is the extra long filter. I’m getting ready to order Doug’s D-port headers for my 65 GTO. I hope they fit as good as your round ports

ANDYA - Pls chime back in on how the D port headers fit on your 65 when you install them

Will do. Still working on assembling the short block. Will post something in the exhaust section once I get the motor in the car, hopefully by early summer.

The braided transmission cooler lines help - metal lines make for a tighter fit.

I had the Doug's for my 69 GTO and while my new engine with stock heads was on the engine stand, I did a pre fit of the headers to my engine.
I found that the headers hit the rear of the pass side of the block when the headers were mounted, this was not some thing that you could see with the engine mounted in the car. Of course an adjustment with a ball peen hammer made life better, but no thrill beating on those ceramic coated headers.