Keep in mind that If I were building a race or bracket engine this would have been an entirely different build.

My goals were a bit complicated but along the lines of a STOCK appearing ( all correct externals for 1971, carb, intake, exhaust, air cleaner, etc.) PUMP GAS (lower compression for safe no detonation street duty engine that would require MINIMAL maintainance (hydraulic cam, no removing valve covers, etc.). There's an outside chance that I could someday run it in a FAST event and I wanted it to be a viable canidate for that as well.

Due to all of the above I didn't run header tests, roller or solid cams, better carb or intake, high compression, etc. Of course in electing to side step all of those I walked away from a couple hundred HP as well, something I can always add or change later if I choose to do so even if I left the compression alone.

The bottome line is that if you want every available HP available to whatever combo you need to make choices with nearly every aspect of the combo, not just one item. Extrude honing is a viable choice but can result in a minimal gain for the money spent, it's not for everyone. As far as cracking due to EH them, I doubt it, you can't even see dimensional changes in the manifolds, they simply look polished inside, I doubt there is any appreciable thinning that could lead to cracking, in fact the deburring action of polishing them probably decreases the likelyhood.

This old saying comes to mind "Speed costs money son, how fast do you want to go?"