I rarely enlarge a intake,there generally bigger than they need to be stock,I might square up the corners a little and ruff it up.
Transfers i don't widen the lower unless I have to,the only part I make bigger is under the bridge,I widen the exhaust side from the corner to the lowers to make it straight which increases the angle more towards the intake,the intake side of the upper I take far as I can to increase the angle again. That's all,nothing is hogged out but the one corner,opening issue the smallest point.
I widen the exhaust to 65% or what the skirt allows.
I also run as flat of a exhaust roof as I can get away with.
That's all I do.
I spend a lot of time on the way the transfers dump and on the shape of the exhaust.
I'm not a number type guy,if I build my best ever 394 at 99 117 82 I won't do another one exactly the same as it because it's not the numbers making it the best,build 20 more like it with the same numbers and not beat it.
I don't see how more intake duration increases velocity,the case will only hold so much and the rest is spit out,I want to get it closed and start building case compression to feed the bigger transfers.
I spent almost 2 years now working on the way I do most saws now just so they would be different,be pretty boring if we all done the same thing.