my valve springs are set up at 590# open pressure. would an .080" wall thickness 5/16 pushrod be ok or do i need something heavier?

How long will the pushrods be? Longer the pushrod the weaker it is.

You will probably be OK. A lot depends on how aggressive the cam and how hard you are going to turn it. It may not break but deflection is a power killer.

Leon

I would pm Todd at Competitionwedge. Give him your combos specs. For the Victor heads that will go on my RB 512,he speced Manton 3/8"x.095 pushrods.

I run Comp's Hi-Tech series in a 3/8 X.080 heat treated w/ 5/16 ball end's and have had good sucsess with them, if you have the clearance run the bigger size, as mentioned before deflection is a power killer.

if you going to get new ones, get the thick wall pushrods... Manton has the bets prices usually and they are the best you can get. You can get stage III .120 wall for about $200 shipped....
Heck Indy wants $180 for a set of there cheapo, cut to fit .080 walls, and your still going to make them.
I used Manton, for the 572 Hemi, and for the 560 CID wedge... both had Pacaloy springs, solid roller cams, with 800 lbs open pressure... I turned that wedge 8K a few times.

Think of the pushrod as a support column or beam... the extra diameter adds a lot of stiffness and strength. Its worth running 3/8" with a perfomrance spring even if you have to make room.

You left out a lot of needed information. Are you oiling through the pushrod? Are you using a 48 or 59 degree block? Are you using offset roller lifters? What heads are you using?

Let me tell you why I ask these question. Years ago, We ran "x" blocks with 59 degree lifter bores/early Arrington heads----I had to use 3/8" pushrods. But, when we went to "R" blocks with W7(or 8 or 9)heads this allowed me to use offset roller lifters and get a short pushrod(7.25"). 5/16" was fine for this application. Even the "big time" oval track builders(Arrington, Petty, Fyrar) used 5/16" pushrods until the small blocks got to 10K+ RPM. Then, they went to 3/8" and even later 7/16". But these pushrods were lightweight and usually came from PPC in Arden NC. I think now they use Trend pushrods.

i dont remember the lenght,but close to stock lenght. indy 360-1 and 1.6 t&d rockers. 59* block. cam lift is .700/.680 solid roller. non oil tru. 5/16 is the largest that will fit.

i use a little bigger cam. 625# open. i use trend 3/8's x .135 wall. w9 heads. just had to notch head a little bit for clearence. seeya.

I used the Manton 3 series 5/16x.120 wall with springs that where over 700# over the nose with no problems spinning the motor to 8000 and these where recommended by Terry Manton.

.120 wall i may be interested. It would take alot of grinding to fit a 3/8 pushrod.

Been running the 5/16 .080 wall pushrod for several years now, just thinking i may be losing some lift.