7.3" push rod length with a Cam_Motion blower cam (0.560 lift) with afr 190 heads and Comp pro_mag 1.5:1 RR's. App... 97ss M6 383 D1.

 

What did you guys end up using for valve covers?
My stockers won't clear now that the longer pushrods and valves are in there.

 

Moroso CB units. When my PR were too long, they hit the supports, which I ground off before I determined that the PR were in fact too long.

If you want, I can dig up the PN when I get home.

 

Thanks man

 

I used the GM polished tall valve covers.

 

Proform centerbolt.

 

BTW, what kind of push rods did you go with at 7.500" long?

I'm hoping you made the investment and went with 3/8" diameter rods or at least a thicker sidewall 5/16".

 

I told them to order the same 5/16" Comp Magnum series I had as 7.150"
(one-piece .080”wall chromemoly)
http://www.jegs.com/i/Comp+Cams/249/7640-16/10002/-1

I'll double-check when I stop by this week to discuss the valve cover issue.

 

Nice choice.

This may sound crazy, but Smith Brother's made me some 7.000" rods with 3/8" OD, and a 0.120" sidewall. Not a typo. Beefy... probably overkill by older views, but when it comes to pushrods there seems to be more and more evidence that stiffer is better, especially for heavier stainless steel valves (compared to Ti or even hollow stem valves) or those with stiffer springs.

In case you don't already know... if you go with NSA rockers like i did, you'll probably have to modify the guide-plates (grind to fit). I went with Isky plates and yes, it took an hour or so of tack welding, grinding, and rechecking to get them all done... but it's worth it IMO. Self-aligning rockers are easier to set up, but at high pressures or increased rod "flex" I get a little nervous of the roller tip "edges" keeping the roller centered instead of large, bolted in guide plates doing the same. (Yes, I realize opinions are all over the place on this issue... it's just a personal opinion )

 

I must have missed something, what grinding did you have to do to you guides?
I supplied TFS guides to the machine shop, I'd never had issues with them before.


FWIW, I'd never use SA rockers on such an aggressive cam.

 

The Isky guides were fine for the 3/8" width, but I needed to grind inside the bottom of the "U" in the guide plate... with only 7.000" rods I was getting pushrod-to-slot touching at peak valve lifts. Probably wouldn't be an issue at smaller valve lifts, or with 5/16" rods, but the combination of the two left me clearancing the u-slots a bit (~1/8" deeper) to get the proper clearances with a good valve stem sweep. YMMV.. though with 3/8" rods, LT1 stud locations (a bit off compared to Gen-I SBC), and a decent variance from stock length rods its enough to check before first start up.

 

Stiffer IS better.


And that pertains to ALL pushrods.

 

A follow up on my earlier post.

The 7.500 push rods did in fact produce the best sweep patten.
But they left the rocker so high on the stud that I barely had 3-4 threads in the nut.
We had to go to zero lash + 1/4 to get them to hold. I bent a push rod trying to run them
with less preload. (rockers popped off)

So I'm in a bit of a bind here.
I have a brand new set of 5/16" comp hi techs in there so the car is drivable to/from the shop
or in and out of the garage, but with that much preload and so little thread under the
nut, there's no way I'm racing it or feeling comfortable driving it around.

Can I buy taller studs for LT1 heads? (like these http://store.summitracing.com/partde...5&autoview=sku)
Should I run shorter push rods?
Or should I run shafties instead?

 

Do they even have a shaft mount rocker set up that will work with the new dart 200cc lt1 heads?

 

Dart castings have the same valve geometry as stock castings.
At least, that is what the Dart saleperson told me.

Jesel gave me this information this morning.