I found some universal AP steel engine pipe to manifold flanges that work perfectly on my 1970 442 engine pipes. They are part # APH-8777 at Summit and only cost $3.99 each, as opposed to $30 per pair from the resto parts guys. They look a little different, but work perfectly. Below I have pictures comparing the Walker #31862 (which is out of stock everywhere I checked), to the AP # APH-8777. The AP flanges require 1-1/2" long bolts. I use grade 8 bolts and never-sieze.

top side

bottom side

 

Good info. Thanks, this is what I love about the good people on this site!!

 

Try stainless bolts.

 

Which way does it go? Is the bottom left image the nut or bolt head side facing up? And I assume you would just flip the summit flange to work?

 

There seems to be some confusion about how they go, so I took some installed pics today. The top side (in my orig pics) faces the manifolds on both flanges.

Passenger side

Passenger side looking up from below.

driver side

 

Clean the manifold and pipe flange. Apply a film of exhaust pipe paste tighten into position.(assuming the whole system has been loosely aligned at this point). Wipe off excess before it drys. Use a thread chaser, not a tap, to clean the manifold threads. Liberally coat the bolts with copper high heat anti-seize. Wipe excess anti-seize.

 

For the record: there's also bolt-together "split-flanges" that can be installed on an existing pipe that's already been flared. They're a fine solution as a repair for flanges that have rotted out.

I have an Edelbrock "Stainless Steel" Tubular Exhaust System (Shorty headers) on an '88 K1500 pickup. The headers and Y-pipe are stainless, but the flanges were mild steel and rotted away to nothing. There's no way to install a new one-piece flange because the Y-pipe is welded together on one end, and flared for the donut seat on the manifold ends. The part number in the photo is for a 2 1/2" pipe. I think this is a Walker part number.