Looking for pictures of stock rear exhaust manifold runners!

**97AutoXVette** · 03-27-2014

Morning everyone,

I am wondering if anyone can post some pictures or links to stock, rear, non-ported exhuast manifolds? Specifically inside the runners??

I am considering porting my stock rear manifold but I want to get an idea of how bad the stock casting is before I decide to embark on that path.

Please post some pictures of the inlets to the stock runners and crossover if you can!

Thanks

**QUICKSILVER462** · 03-27-2014

I do know that the head side flange weld on the inside of each exhaust port protrudes approx. 1/8" reducing the I.D. by approx. 1/4" over all. The down pipe flange is the same way, and the o2 bung has a large bead around it on the inside too, that is the best I can describe it I just don't have pictures of my old manifold. I have a zzp ported rear manifold on my car and defiantly noticed an improvement after installation, smoother, better sound, and picked up 2 mpg in the city driving.

**97AutoXVette** · 03-27-2014

Good to know and thanks for the detailed description! After looking at the stock castings on the front manifold, I figured there were improvements to be made on the rear as well. I will likely pull it off at some point and go to town with my dremmel. If anyone has pics feel free to throw them up still!

thanks again

**Booba5185** · 03-27-2014

I can get ya some pictures later, I just pulled mine last weekend when I put my headers in.

**97AutoXVette** · 03-27-2014

Originally Posted by Booba5185

I can get ya some pictures later, I just pulled mine last weekend when I put my headers in.

Fantastic. You da man.

**GrandPrix06GT** · 03-27-2014

Front is more important than the rear I believe, hence why they make plugs for the front crossover. But here's pics..

**wa04compg** · 03-27-2014

Front is cast rear is not...plog for the front and 3in dp would be best if you want to keep manifolds

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**97AutoXVette** · 03-27-2014

Nice. Thanks for the pics. I swapped my front cast manifold to the PLOG last night. I can confirm that the casting for the front has a nice block in each of the exhaust ports coming right off the head. Would like to see a close up of the rear manifold to see how each of the inlets on those ports look. From the picture above, looks like they may not be as bad.

Thanks again for the pics GrandPrix06GT !!!

**GrandPrix06GT** · 03-27-2014

Yup no problem, I think the rear is the top one only, I'll go outside n snap a few up close pics if they're still in the box I left em in. Should be similar to the front tho I'm assuming.

**GrandPrix06GT** · 03-27-2014

Nope, doesn't seem as restrictive as the front at all. They're pretty opened up compared to that swoop that's on the front.

**97AutoXVette** · 03-27-2014

Excellent, that is exactly what I wanted to see and compare. Looks like the rear manifold is not as restrictive after all. That turn in each runner is unfortunate, but other than that, not too bad. I still hope to pull mine off and port it eventually. Maybe that is why I can't find ported rear manifolds on ZZPs website anymore?!