OK-- I have been collecting this info for awhile... Following are links and pics to all of the 3rd gen exhaust manifolds that I have discovered and then all of the 2nd gen exhaust manifolds that I have discovered.
PLEASE know that I a NOT endorsing any one of these over the other in terms of performance... nor am I saying that they will increase performance, although many of them claim to... IMHO, they are simply some VERY cool looking exhaust manifolds that ALSO fit our trucks. And since the OP asked about using a 2nd gen manifold on a 3rd gen truck, I feel that it would be appropriate to post pics of BOTH types in the this thread!!
I , too, LOVE the idea of using a centered, 2nd gen exhaust manifold on our 3rd gen trucks. However, several of the equal length, (non-log type) manifolds, are ALSO beautiful, though just for the helluva it, I will aslo post a pic of a TOTALLY ugly one.