Sounds like a pretty good plan...but why the tall deck block? Do you already have one? The reason I ask is because then you get into having to buy some 'strange' parts because of the taller deck--intake (or use spacers), header fittment can be a problem, distributor, oil filter may not fit as well, etc...Yes, they are good for bore and stroke projects, but you get into some other difficulties quite often. If you use the 781 heads (good choice), plan on a domed type piston. They have a rather large combustion chamber, so to build a decent comp. ratio (9.5 or 10/1) you have to use a domed piston. Other than that, it's easy to build a 500 hp, 500 tq engine with a big block. It all depends on your other parts choices. Dont go crazy with the cam....I know you want a lumpy idle, so everyone knows you have something nasty in there, but it's easy to go too big, and then all your hard work will be down the drain. You will have a very lazy combo, that only wakes up after 3000 rpm's! You dont want that. Get a tighter lobe seperation angle (LSA) on the cam if you want chop up the idle a bit...108 or 107 will give you a lumpier idle, but you can still keep the duration and lift at a decent number so you wont kill your bottom end. The only thing you will give up by doing this is that your power band will be a bit smaller, but only slightly. The up side is that you will reach it quicker! Any of the cam co's will grind a custom cam for you if they dont stock something you want. John