All,
Looking at buying Roller Rockers soon.
Wondering if it is worth getting standard 1.5:1 rocker arms, or is it a better idea (same cost) to go with 1.6:1 ratio?
Car is all metal '72 Demon, 408 w/hughes stage 2 prepped eddies and port matched air gap.
Comp hyd Roller .541/.537 lift, 280/288 dur.
should be around 10.5:1 comp.
850 Holley DP (hope to send to Thumper)
904 trans, 3500-4000 stall, 4:30 gear.
I think I've explained everything as far as the combo goes....
Is there a gain w/1.6 ratio rocker arms?
If so, I need to buy them regardless.....so....
Looking for pros and cons.

Thank you all!!

Wally.

It depends. (I'm sure I beat someone else here to the punch with that particular response. )

I'll take a (s.?)w.a.g. and say what you described won't see much, if any, gain. However, the higher ratio may also result in your hydraulic-roller valve train going unstable at an earlier RPM than 1.5s.

Just 'cuz they cost the same doesn't mean you "should" get them.

My unsolicited vote: NO

Changes rocker geometry! & you would have a .577/.572 There would be a possible HP gain. I would check piston clearance.

Not enough info posted to answer this
!. street, strip, street and strip
2. how quick has it gone or don't you care
3. if you do care how fast do you want to go.
reason I ask i I see more important issues that you could address and go MUCH quicker.

1. street, strip, street and strip
Strip 80%/Street 20%

2. how quick has it gone or don't you care
Have not run it with this engine - the only engine parts I've purchased so far is Heads/Intake and 1 7/8" TTI Headers

3. if you do care how fast do you want to go.
I need to run 11:50's at least

On a SB it helps with pushrod angles a tiny bit. For the same price I would get em but like pitsburg said there is other stuff that could help you go faster.

If its in anything under 3400 pounds you should have that covered. These small blocks LOVE high stall convertors and yes you can run them on the street easily with proper cooling. My sons 3200 pound Duster went from 11.10 to 10.60's just from going from a 4400 stall convertor to a 5600 stall with his 360 engine. And it only had a 520 lift Racer Brown Solid lifter cam. A restall would pay WAY better dividends than a 1.6 rocker. Next move I would suggest is a slightly ported Victor340.

Since you Need them anyway, Absolutely I would go with the 1.6.1 ratio.

If I needed them I too would go 1.6 especially on the intake side. If you are running 3/8 pushrods make sure you dummy it together to see if it will need any clearance grinding.

If its in anything under 3400 pounds you should have that covered. These small blocks LOVE high stall convertors and yes you can run them on the street easily with proper cooling. My sons 3200 pound Duster went from 11.10 to 10.60's just from going from a 4400 stall convertor to a 5600 stall with his 360 engine. And it only had a 520 lift Racer Brown Solid lifter cam. A restall would pay WAY better dividends than a 1.6 rocker. Next move I would suggest is a slightly ported Victor340. (/quote)

I have not ordered a convertor yet...
I'm thinking of starting a new thread asking specifically for best ideas to make the car run 11.50.

I've owned the car since '83 and ran it until the mid 90's.
I'm learning so much about how everything has eveolved (cams, convertors....)
Every bit of advice I really appreciate.
Going on 50 years old with a bad body from playing hockey my whole life makes this a slow process, but I come here for inspiration.

Thank you guys.

Wally.

if it's a aggressive cam lobe i wouldn't mess with the 1.6 rockers too.

here is an old dyno article that shows what can happen when you try to ask for too much from a hydro lifter...

http://www.hotrod.com/articles/mopp-0510-440-engine-dyno-test/

Not a good comparison. Wally posted he has a hydraulic roller and its also a smaller cam.

that cam was a hydraulic roller and duration was 275 @ .006"

1.7 ratio though vs. 1.6

all i'm saying is if it were me, and for sure was going to keep the hydro lifters, i'd go modest on the rocker ratio.

IMO, a 1.6.1 is a modest rocker ratio, 1.7 1.8 not so modest. especially with his posted cam.


But your point is good and should be taken into consideration.

Go with the 1.6s, and here's why.

The higher ratio will help gain back some of the cam lobe intensity lost due to the lifter to pushrod angle on a 59 degree block. You will not gain enough extra intensity to make the valvetrain unstable with the recommended springs in most cases, but it doesn't hurt to check with the cam manufacturer to be sure.

Second, if you should go through the effort to make sure your rockers are properly set up for correct geometry, the 1.6s are much easier to correct on a small block, and can be worth a little extra power up top as well. I said could be.

And third, if set up with proper geometry, a roller rocker will have more area under the curve (intensity) than a stock type rocker, as well as a more accurate ratio. That area increases with a higher ratio rocker, and if everything is right, will be capable of making more power, just like a larger cam. But, it has to be set up right!