I'm most likely getting some Comp 1.6 RRs.

Should I buy a pushrod length checker? or just buy some pushrods and see if they'll work?

Also, my cam which is a Comp 268xe will go from a 477/480 lift to a 509/512 lift I believe, will this up the powerband on the cam?

Right now it makes power from 1600-5800.

 

Change in rocker ratio does not by itself require a change in push rod length. However, if you haven't yet checked to determine the push rods you need, which of course can only be done with the heads installed, you need to; and you might as well do it with whatever rockers you're going to use, since that way you only have to put them on once.

Get a check push rod.

The rockers will not significantly alter the power band, since the duration remains essentially the same. It should simply increase the power output above what it would be with a lower ratio, if the other induction system parts can supply the additional flow.

 

Mark: I noticed on the Proshaver site that these heads come
assembled with +.100 longer valves, resulting in a higher than stock like spring installed height. (stock is 1.68 to 1.75)
These longer valves are fine but may need longer push rods
to get proper rocker arm geometry.
You could mock up the head on your block and use your old stock push rods and a rocker to check this.
You would need 1 solid lifter to check this properly.
A hyd lifter's plunger will compress during the test.
You set up one valve with "0 lash" with a solid lifter
and rotate the motor over by hand and observe the
travel across the valve tip the the rocker tip makes.
There are various themes on what is "correct rocker geometry" but
basicly your looking for a situation where the rocker contact
point goes too close, or off the edge of the valve tip.
There really is no way to predict your rocker geometry
without checking it yourself.
It will likely be just fine but is worth a look while your there
so that the rockers and tips of the valves are not damaged.
As a note: A thinner head gasket or shaving the heads a little to increase compression has the same effect as installing a longer pushrod, on rocker geometry and valve tip contact travel.

 

Mark,

With the pro heads you need +.100" pushrods. Also what size studs do your heads have it beleive mine are 7/16"

 

thanks ME, even with 1.6 rockers, +.100 rods will work then?

I believe mine are 7/16ths too.

 

They should work fine.