Cast Exhaust Manifolds (Approximately)

[Orange Crate]

After 57 years my 2.5" stock exhaust manifold cracked. Wow what a shame, these things really woke up my 406 but looked stock. Oh well on to the fix. I ordered a set of 2.5" cast units from Summit. So here are the pics comparing them to what is left of the stock pieces. I have a saying that things made in the Pacific Rim are "approximations" of the real thing. Close but.....these new ones are not going on my truck. First pic is...well yea that happened. Second pic is the "new" high performance? Third pic is the old single exhaust port. One of these things is not like the other.....On this engine I need every square millimeter of flow (No I am not going with headers). Now I am looking at the TruRam set. Anybody have a set of those? I have AC so I think these will interfere with the new Alan Grove brackets I just put on.

[Ziegelsteinfaust]

I got 2 sets of the Dorman ram horns from Summit, and they looked good. With just being rougher then factory versions, but no misaligned ports like yours.

If by true ram horns you mean the polished ones you can get from speedway that look rounded, and swoopy.

I gave my dad a set of those, and they looked very nice to me

[Orange Crate]

Thanks for the input I'll have to call them about the port size/design. I was looking at these as a substitute for the original Corvette manifolds. The obstruction that can be seen in the port isn't misalignment it is how they are cast. The port on the other end is cast the same way and also the other manifold in the set is cast exactly the same. It seems odd that the manifold is a 2.5" high performance unit but with a complete face plant in the port design, again it is an approximation of the real functional high performance piece. The original Corvette manifolds can flow pretty well up to about 4000 rpm which is fine for the way I build my engine to tow. I have an RV cam that is "all in" at 5000 rpm, so there is no need to have big flow numbers above that as you get with headers.