After some experimenting and extra parts purchase that are now on shelf thought i would put up an air filter fit posting.If using a cowl hood,prob no problems,but here is the tallest filters for a stocker.It all depends on the ht. of the engine install so here is an initial measure of the room you may have to work with.With a straight edge and some Q-tips on the front fenders and slight touch of the top of the filter cover is the starting point
There are two filter bases to use either the GM 6422188 http://www.classicindustries.com/produc ... 22188.html
or Allstar ALL25900 kit
Cut some foam at diff hts. and use the straight edge for a max filter element ht.
Cutting hood braces adds to the filter ht.Partially close hood and trace around filter cover with white pencil
I did this with the radiator out and no front acc. on the engine reaching up and tracing,may be more difficult on a running car.trim with cutting wheel
Carefully did this with hood painted and had no problem.
Traced and cut some filler foam I had but any type of other material may work for the re-enforcement gaps created
Inserted the fillers and got some strong black adhesive to re secure the braces tight to the hood sheet as well as 'glue in' the fillers.
Now the filter cover extends up where the braces were
1/4' from the hood skin is ideal
3 1/4" for my car so searched for that size air filter
And job done.