[Marv D]

I agree 100%,, 10.25 with aluminum heads, the cam spec says intake closing is 44 after,,, your dynamic compression should be plenty tolerable of pump gas,,, that is all assuming the 10.25 is a true calculated static compression from measured volumes?

I do want to touch on something again,,,, you only make power by moving air and fuel into, and out of the chambers. The more you move, the more power you make,, simple fact. And a 200cc port is going to 'allow' more air to flow than a 170cc port. You ARE leaving potential power on the table with the 170 e-tec's,, in favor of something that I don't know I 'totally' agree with the thought that the 170 e-tec's offer more mid rpm torque. The whole Edelbrock line concentrates on this thing called 'port velocity'. Without good port velocity fuel falls out of suspension, you get poor cylinder filling, reversion, all sorts of things that cost power. I have never seen any real back-to-back comparisons of the E-tec 170 and 200, but I would suspect it's the great port velocity of the e-tec 170 that did so great on 406 I built for my friend. I am quite confident the 200's are going to share the same port technology and high speed velocity of it's little 170cc brother. I'm not convinced the 200 would be a 'bad' choice for a larger small block like this.

What all this is saying,, FOR WHAT YOU ARE DESCRIBING... the 170 is probably, and may well be the better choice. If you will almost never see the high side of 4000rpm, the 170cc version will fill the bill on the street very VERY nicely. BUT,, remember,, this 450+HP magic number is most likely up around 6200+rpm. NOT at 4000. IMO any 170cc port, no matter how great it's port technology and velocity is, is going to be borderline trying to feed a 380+ cubic inch small block up in the upper 6000rpm range.

You have a bit of a catch-22 deal going on IMO. Horsepower is simply torque , times RPM, divided by 5252

Your 420 ft pounds of proposed torque,, at 6200rpm will be real close to 500HP

at a more believable small block torque peak of 4200-4600rpm ,,, more like 330-360HP

When you give up RPMs, you give up horsepower. And it's apparent your giving up 'potential' horsepower with the head that is going to inhibit rpm's in favor or 'potential' mid rpm torque. All just something to think about.

I don't know the arrangement you have with your builder, or if they have a good superflo dyno,, but for the $500 most shops charge,, a engine dyno session is worth EVERY PENNY if for nothing but to tune the motor to a sharp tune. Take YOUR headers, YOUR carb, YOUR distributor and spend a few hours on the dyno and it accomplishes a multitude of things. First it dispels any HP and torque 'CLAIMS', it breaks in the motor, finds any assembly errors / leaks, and potential problems. And,,,, spending a few hours / few hundred bucks getting the tune RIGHT may save many fold that much in wasted fuel and other items you waste searching for the right tune. And if they tell you they have dyno'd one just like it and know what it makes, NO THEY HAVENT, not with YOUR carb and YOUR headers and YOUR exact combination of parts and pieces going into YOUR chassis.