Here is the first rule I like to say with FE heads. ANY well ported FE head can support well over 500 hp.
However, when you get to unported stuff, the raised runner emissions/unibody/truck (C7AE-A, D2TE-AA, C8AE-H) are limited to about 400 hp. Mostly because of crappy obstructed bowls, but also because of sma;; intake runner size for a deep breather.
Again though, port them and rock and roll, with just a mild rub and decent valves, I am getting 277 cfm at .550 out of a set of D2s, arguably some of the poorest performing iron heads out of the box.
C6AE-R is an odd one though, especially on the exhaust side, they have a raised exhaust floor AND a lowered roof, but they have the good early intake port. In addition, they also have the ability for the CJ exhaust bolt pattern. They are NOT like a C8/D2, they basically have a smaller port at exit, and can be opened to either an erarly/CJ or a GT/truck gasket. Pic from the FE forum
So that makes it a very universal head, it can match any of the exhaust port locations, it can match any of the exhaust bolt patterns, and it has a decent intake port. With porting, like any other head it responds well
So it is
absolutely a poor man's CJ, but not because of some magical performance, but because once you get grinding on that exhaust port roof, drill the additional holes, put the big valves in, you now can run CJ headers, and have a basic design much like a CJ.
Or, you could call is a Poor Man's hipo GT or hipo truck head too, by doing the same thing, but leaving the exhaust roof low and working the floor a little and drill for GT pattern
For a truck though, be certain you know which header location you have. I used D2s because they were a perfect match to my Hedman headers and really, knowing we would port them, it was just as easy to use a known good set of heads. If your headers don't match, you'll be crying later because it will take some level of effort to make them seal, where the correct port is bolt and go.
