3/8" pushrods with Stealth heads?

Can these be used? I've heard that you must use 5/16"

I found I could not get 3/8" pushrods to clear the heads with 1.5 ratio rockers. I had to do some filing/grinding to get them to clear. When I fitted 1.6 ratio rockers I went back to 5/16" pushrods so I didn't have to grind them again.

68LAR, I'm working on this stuff myself right now. From what I understand in order to use 3/8 push rods with Stealth heads you have to open up the intake push rod passage. The exhaust is supposed to be ok. I also understand that 5/16 will work without modification to the heads and you can use them if your spring pressure is not too high . I am planing on using 5/16 push rods with the stock springs that came with the heads(checked out by my machine shop)and the Comp XS274 cam 502/236 intake and 520/242 exhaust. This was OK'd by fast68(Dwayne) of Porter Racing heads. If I am incorrect someone please correct me!
mIke

Thanks,
A friend of mine is about to install a set of the Stealth heads and wants to run the 3/8" push rods. He was told that they won't work. He runs the same spring that I do. 150 on the seat and 375 open. If only the intake side needs opened to make the 3/8's work he may go that route. I'd be skeptical with a 5/16" working at 6500+ rpm. He is also going to be running the 1.6 rocker arms. What area of the pushrod passages needs opened, using a clock for positioning. Like 12 o'clock, 3, 6 & 9 o'clock? My Eddy heads needed very little removed from the 9 o'clock position. And I mean very little!
By the way he is running a solid flat tappet comp cam.

It depends on the height of the lifter cup, with a HYD roller a very small amount of clearancing to be done right at the top of the push rod hole, just touches when using COMP rockers,,, remember the pushrod moves away when lift begins.

I've also have had clearance issues with Steath heads and 5/16" pushrods and only on the later castings. The first time I thought it was a fluke so I didn't mind pulling the heads off and rework them. The 2nd time it happened I was a little upset. Since then I automatically clearance them right out of the box.

I use Crane 3/8th's pushrods and Crane iron 1.5 rockers with my Stealth's. I'm using the Mopar 296/557 cam,and Comp springs and retainers/locks. I had to open the intake pushrod holes a bit,but all I did was mock up the heads,and used a marker where they didn't clear and ground away.Wasn't much,and I maybe had an hour's worth of time doing so.

Cab had a bunch of pics of the 3/8s hitting stealths

Not to be a sarcastic pr!ck, but you need to clearance the part of the head that hits the pushrod. Different rockers, lifter type can all affect where the clearance issues will spring up. My favorite method is to use some blue dykem on the head, install it with a gasket and a few bolts, install the lifters, pushrods and rockers and roll the engine over a few times. This will usually leave a shiny spot on the head where you need to address things. If the interference is bad enough you won't even be able to get the rocker to seat on the pushrod, and if you try to force it, expect a bent pushrod.
Hope it all works out well for you.

I have a set of the first heads.My 440 rins .588 cam with solids.I run Crane 3/8 alloy rods with Erson iron rockers.Mine just clear.I ran it for a while after the install and rechecked it when I adjusted the valves.Never saw any rubbing.Rocky

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I have a set of the first heads.My 440 rins .588 cam with solids.I run Crane 3/8 alloy rods with Erson iron rockers.Mine just clear.I ran it for a while after the install and rechecked it when I adjusted the valves.Never saw any rubbing.Rocky

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You also need to consider push rod deflection. Also, the only issue I had with their first casting's was h2o dripping on the floor at the dyno. The head was cracked from the git go, but 440 Source stepped up to the plate and replaced it.