Ih exhaust manifold spasers for 426
Printed From: Unofficial Allis
Category: Other Topics
Forum Name: Pulling Forum
Forum Description: Forum dedicated to Tractor and Garden Pulling
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=210159
Printed Date: 09 Apr 2026 at 7:01pm
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Topic: Ih exhaust manifold spasers for 426
Posted By: dbounds
Subject: Ih exhaust manifold spasers for 426
Date Posted: 22 Feb 2026 at 9:33am
| I read a post years ago on putting 400 series IH exhaust manifold on 426 engine. My original series one manifold is shot on my D21 puller and would like to find who made adapters for the IH manifold. Could not find that old post. Any ideas? Doyle Bounds Missouri Mule D21 |
Replies:
Posted By: DrAllis
Date Posted: 22 Feb 2026 at 1:19pm
| Probably was me. I made them for my D-21 that I had some 30 years ago. With a Bosch "A" pump I was able to spin an Air Research TO-8 turbo. I made them out of 1 inch thick steel blocks. The holes that attached to the 426 cylinder head were countersunk and used short 1/2" NC Allen head bolts. The DT-400 series manifold bolt holes were top and bottom so the blocks were thick enough to be threaded and hold the IH manifold up against them. It was very time consuming to make, as the IH manifold is only two pieces, instead of three like the A-C manifold. So you fudge a little bit on how you make the spacers. The A-C ports are rectangle while the IH are square, so you spend a lot of time with a die grinder blending the spacers to fit each port. It was all worth it, but will try your patience getting it done. |
Posted By: dbounds
Date Posted: 22 Feb 2026 at 4:33pm
|
DrAllis: Would you mind talking to me about spacers? Is your number (319)360-4788 ? if so when would be a good time for me to call. Doyle
|
Posted By: DrAllis
Date Posted: 22 Feb 2026 at 7:09pm
| Nice talking to you again, Doyle. Good luck on the exhaust manifold update. |
Posted By: WF owner
Date Posted: 23 Feb 2026 at 6:39am
|
Doc, if you charged us all for your advice, you would be a millionaire! Thank you for all you do for all of us!!!
|
Posted By: cms
Date Posted: 19 Mar 2026 at 5:39pm
  Here’s an option. |
Posted By: DrAllis
Date Posted: 19 Mar 2026 at 8:14pm
| The reason the IH-400 series manifold is superior to the A-C original manifold is because the exhaust gases basically take one turn out of the cylinder head port and then head down the tight sized runners. The tight runners keep the exhaust gases from expanding until they hit the turbo exhaust wheel, which is more efficient. The manifold is also designed for the "pulse" effect by splitting 1-2-3 and 4-5-6 to separate runners. This manifold pictured still takes two turns for the exhaust gases and the runners look to be large which slows down the exhaust gases speed. It is split ports at the turbo mount but that's about it. |