For kicks I had my heads (906) flowed and they came in better than I expected-260@.500, 265@.600, 268@.700. My cam is a solid .543/.529 lift and 253/256 duration @ 50. This is on a 451 (400) running a tunnel ram. Will there be an advantage to moving my rocker ratio to a 1.6 or even a 1.7? The car runs very well now (10.90 @ 3200lbs) and part of me wants to leave it alone. But if could pick up a tenth or two for less than $300 that seems like a good thing.

From your flow numbers the 1.6 or 1.7 would help you
out but I dont know about $300... all you have to do
is the intake rockers

Sure, if the flow isn't backing up or behaving funny at the higher lifts then you should always pick up some power by increasing the ratio. You need to have the right springs of course and enough clearance everywhere.

I just finished up some dyno testing with my 505 and we picked up a solid 10 hp when going from 1.70 to 1.85 on the intake rocker arms. We didn't change the exhaust rockers since often times you don't need more lift there.

So do I only need to look at changing out the intake and leave the exhaust alone? I can't tell if that is what you are saying or if you are poking fun at my $300 rockers(which is not a problem as I am cheap). I was just thinking about using a set from 440source. Which ratio would put the motor in the best overall condition from power and reliability? It is really a very mild build as I am shifting at 5800.

It will help you make some more power with the increase
in rocker ratio. You will only need to install the
intake rockers..... if you have the valve to piston
clearance... the 1.6 will give you a lift of .579
the 1.7 will give you .615 lift you should check
the springs for the added lift

There is not a simple answer to your question. Typically you'll make more power by increasing the valve lift but not always. Typically the engine will want more intake lift than exhaust but not always. Some camshafts won't work well with higher ratio rocker arms but usually you'll be okay at lower speeds.

To get a better answer you would need to know which lobes are on your cam and what they were designed for. You would also need to know how well the heads work at higher lift. But nothing wrong with just buying some parts and trying it either.

I guess that is some of the information I am looking for--what in the combination makes the ratio increase work better in some situations vs. another. It seemed reasonable to me that my smaller cam may response better especially seeing the heads are willing and able, however there is always a point of diminishing returns, which is why I was asking about the 1.7s. Like I said, I feel like the combo currently works very well for what it is.

I actually need to be spending my time working on the suspension, as the car traps at over 124, but has a hard time breaking a 1.60 60 ft. However, I will have to wait on the weather to tackle that one, so for now I am left to contemplate rocker ratios.

what in the combination makes the ratio increase work better in some situations vs. another

Always helps if the cam is too mild, or the lobe centers are too wide.
Reason #1 why "sometimes they don't work": the overlap is already about optimum, and more = worse.

Could be lots of things make them work or not work. Mabey they increase power but the rest of the combo is already over taxed. Also could be a valve spring loseing control of the valve. Mabey the cam is just plain too big already and extra lift won't increase cylinder filling. Might be a too narrow of LSA and it could make for excesive overlap and dilution of the A/F mix. Probably a hundred other things that could make a differance.

With all the factors involved, it seems like Andy may have summed it up best- sometimes you just have to experiment. Like I said I am pretty tight when it comes to turning loose money, so I do try to research as much as possible to ensure that I am not sowing in a place that will yield no fruit. Thanks for all the input, but I guess it does seem like that it would at least be worth a try in my situation.

Anyone have any 1.6 Crane ductile rockers laying around?