Hi all! I'm new here. My current project is a 1978 chevy K10 stepside. It has a 455 oldsmobile under the hood. I have a question about exhaust manifolds. My engine came out of a 1973 olds delta 88. the one manifold has dual exits on it and I plugged one for my dual exhaust. No they have crack and I need to replace them....So can the X Z ones fit??? I know I can get repro ones from thornton I think it is and I would really rather not have to re-do my exhaust because the orrientation was off where the pipes hook up to the manifolds. So what do you guys think I should get? I already know I don't have room for headers. Thanks for your time guys. I appreciate any info and help I can get.

 

Welcome to CO. It would be hard to say since your engine is in an unfamiliar body but I would guess the WZ manifolds would fit as they are pretty tight to the engine. However, I don't know if they will mate to the existing downtubes you have now. Maybe Joe P can chime in here. I am going to move your thread to the new members section so people will welcome you and you might get a better answer than mine.

 

Welcome to the site! I've got an Olds 350 in what was a diesel 1979 GMC 1/2 ton sort wide bed. I don't know for sure if they'll fit but it seems like there's a lot of room in that engine compartment. I would be optimistic that they would but hopefully someone who knows for sure will be able to comment. John

 

The easiest and cheapest thing to do is to remove the exhaust manfiolds on the vehicle now and have them repaired. Cast iron can be welded if an experienced welder does it the right way. Oldsguy and I both had a shop in Lee's Summit, MO weld numerous cast iron parts (including exhaust manifolds) with great success.

 

Welcome aboard

I'm with Dan

Let's wait and see what Joe says. He be de expert.

 

I don't believe the down tubes will be in the same location as what you have now if you replace with the W/Z manifolds. The W/Z manifolds will work as I have see this install with W/Z over on ROP. The welding of your current set seems like a good option

 

Thanks for all the replys guys. I might weld them up I think. then I don't have to change anything. this summer I'm gonna install some electric exhaust cut outs on it so I can open it up. I'll have to post some pics of it on here as I go. Thanks again for all the reply's it really helps when you chat with people who have been there and did that and whatnot.

 

The W/Z would be a good replacement for what you have now and would help the flow a bit over the ones you have now. Everything should bolt right up.
Lets put it like this. I had an 80 Cutlass that started life with a 260. I bolted a 350 in and used the stock exhaust. Next came a 455 and same thing....stock exhaust. Bolted right up with no issues. I choked the hell out of the 455, but it bolted up with no issues what so ever.
The only thing that MIGHT happen is the pipes could hang down 1" further in the front than they do now, but with the truck that should not be an issue.

 

Keep it up and I'll need a double door for my office to fit my head through...

I'd go with the W/Z manifolds, but you will need to have the head pipes modified to fit the outlet locations. Welding the current ones works if you don't care about the restriction. Obviously you need to find someone who can weld cast iron. Also, if the cracks are at the flange, you'll need to have them remachined after welding. If that's the case, I'd replace them.

 

This is very important. I had a set of W/Z manifolds repaired by a "good ole' boy" shop. The cast iron weld was great; however, they resurfaced the exhaust manifold to head mating surface with an angle grinder... not the most precise machine tool available.