I was looking into changing out the bulky (difficult to put on and take off) headers on my '68 Firebird (which I intend on switching over to a Ram Air II or IV eventually) and someone told me the Ram Air manifolds look a lot better than the stock ones do. So I went looking around and found I liked the look of the 70-81 manifolds a lot more than I liked the 67-69 ones.
I was wondering if I can get those on w/o much difficulty or should I just stick w/ the headers I have?
The manifolds will be from Ames or Classic Industries.

There is no doubt they will fit the engine just fine, but you will have to fabricate new head pipes for your exhaust system, and you may run into clearance issues with the steering gear.

Why not just buy reproduction first gen long branch manifolds?

The clearance issue was what I was most weary of.
As for the 1st Gen RA manifolds vs. the 2nd Gen manifolds, I liked the way the 2nd Gen's looked on the engine a lot more. They looked a lot more like headers

Have a set off a 70, and since front end and engine is out to install a midplate(bare block in for mock up), i'll toss a set of heads on and see how "doable' it is.

Passenger side fits no prob.
Driver side no way do to the steering gear.
FWIW, the 1st gen style flows better.

I think I'm going to stick to the headers for now. Thank you Yellowbird and Region Warrior I might have been stuck w/ a pair of reproduction manifolds that wouldn't have fit if you guys hadn't helped me out.