Renix intake to HO head and exhaust

88 Wagonman

New member
I tried searching over the past couple of days and couldn't find much info on this, but I went ahead and did the trial and error work. For the purpose of helping future searchers, here are the details on my latest project.

I have been running 98 longblock (HO head) with the renix intake and exhaust bolted up even though they are mismatched. I have not run into any problems with the way it runs, it has been several years now. I have started gathering parts for an intake swap, but I am not quite ready for the whole swap, so I decided to just do the exhaust. The reason for this is that the exhaust leaks (cracked manifold) are getting into the heater and making their way into the cab, probably due to my mechanical fan delete allowing the fumes to build up.

So, on to the exhaust swap. I already have the EGR plated off, so that is a non issue. I replaced the gasket which was for the HO head, and started to bolt it up. The exhaust bolted up fine, as it should being an HO head. You also need to replace the downpipe because the renix is different than the HO, but it bolts right up to the cat. Now to put the intake back on. This is where I ran into an issue. The problem is that the exhaust flange does not allow clearance for the renix intake to sit down at the corners. I suppose that you could grind the corners of the intake to clear, or even perhaps the exhaust flange, but I did not like these options for a couple of reasons: 1. I felt that I would have to remove too much material from the intake 2. I did not want to modify the exhaust since I plan on replacing the intake with the proper fitting one later. So, I decided to notch the holes for the dowel pins so that the intake will still be aligned, but now will sit a bit higher than it did before. Now the intake ports are actually aligned better than they were before, and everything seems fine.

I will post an update of any ill effects that I may run in to in the future, but for now I am pleased with the results.