Trick Flow heads are great, I've been using them for almost two years now. I had one of the very first sets that they shipped. I think you are on the right track by building a 505. (If that block hasn't been bored out already then it will be a 505 on the first build). Use the 4.25 crank, 7.100 chevy rods and pick the correct pistons to give you 10.5 compression. Use the TF 240 heads and for the street a Performer RPM intake is probably a good choice or go with the Trick Flow intake for a little more racy look. I have not used the TF hyd roller cam but it should work just fine. That cam is 243/247 which will have some rumble to it even in a 505. If you don't know how to tune a carb you'll be asking for help. If you are more of a forward thinker then skip the carb and go straight to EFI. I'd recommend a Holley Sniper setup on that engine. Here is a video if you are interested of my 470 on the dyno with Trick Flow heads and a Holley Super Sniper:
I am not the expert Andy is, but, I just pulled a cam out that is very similar to that one, except mine is a solid roller. It doesn`t have enough vacuum for my fuel inj. system. I`m having one ground "as we speak" ? , that has a wider lobe separation and is 6* smaller, lift about the same. I`m only supposed to lose 6 h.p. , but gain 4 ft pounds of torque , (like that is a big worry w/ a 505 !)
Your f.inj system may be diff., and be able to work w/ low vacuum, I don't have a clue, something to think about !
