I'm building a very similar setup, with the 1.75 1.50 valves in a 302 head on a '73 318 in the same car with a Hughes 1019AL. This one will run hydraulic lifters and stock rockers which is not as big as you are going with your valves.
It's running a high velocity intake and small primary carb with KB pistons at .012"
One thing I should mention is that the 302 head, using a factory valve spring retainer and factory stem seal, there is just about .500" total/ actual lift clearance between the spring and the valve stem guide.
If you plan on running any higher than that in measured lift, you will have to get the valve stem guides trimmed down and you will have to check valve to piston clearance through the critical crank angle, from about 15° BTDC to 5° BTDC and again from 5° ATDC to 15° ATDC with stock pistons.
If you are running the stock flat top pistons, the largest cam I'd suggest with that engine, for your application would be the 1523AL, but again, check your valve spring to valve stem guide/ valve stem seal clearance and valve to piston clearances with those valves.
http://www.hughesengines.com/Index/...dWxpYw==&level3=U3RyZWV0L1N0cmlw&partid=21842
Everyone has their preferences with cams. I like Hughes, because they run a true .906 wide lobe (factory chrysler) which helps carry load, rather than the Ford/ GM profile cam grinds with those lifters, although they all work well.
The above cam I would suggest, mostly for it's duration measured at .050" lift will be good for street.
The Whiplash cams have a lot more duration, which adds overlap and while it sounds mean, kills torque on the bottom end until you bring RPM up. It also makes valve to piston clearances in the important crank angle map a bit tighter, because the valves stay open longer. Intake chases the piston down, piston chases exhaust up, so you've got to be sure that the edge of those valves will have .060" int./ .100" exh. clearance before contacting the piston.
Most applications at .500+ lift require a valve relief in the piston.
Another thing to take into consideration is that you will lose lift from pushrod angle on a small block. About .010 or so, depending on crushed thickness of the head gasket. I'm not sure about roller rockers from a 273, but the hydraulic 1.5's are closer to 1.44:1 ratio, so you lose a little there, too.
Hughes cams have a 3° advance when put in at zero, which helps close the intake valve sooner on up stroke, for more cyl. pressure.
The choice of brand and cam profile is up to you, but for what you are using the car for, assuming you have a stock torque converter, I would suggest shopping for a split ratio cam with something in these ranges for good torque from idle, which is what you will be using the car for;
.460" to .472" intake lift
.488" to 509" exhaust lift
210° to 220° intake duration
219° to 230° exhaust duration
Those duration figures are the numbers you want measured at .050" tappet lift. Not total. They do that for consistency, because it is difficult to measure duration at the beginning of 0 lift from the rest of the base circle, consistently.
If you go any higher than that, your power range will start to come up in RPM, which is not what you want for a stock stall converter or something that needs torque from idle.
Hope this helps you look for something. There are less expensive cams on the market. Shop Summit and Jegs as well as other manus. Buy their suggested spring and lifter to match.
