1970 351W Stock Head Rocker Arm Conversion

[zgreatwhite]

Instead of doing the sensible thing and buying a new pair of heads, I would like to convert my stock 1970 351W heads to either adjustable rocker arms, or roller rockers...though adjustable rocker arms are preferred.

I have not found any information on this conversion for stock heads, though there is plenty of information for doing this to aftemarket heads(Edelbrock, AFR, etc.). It seems I have to pull the pressed in studs, and replace with screw in studs.

Any advice on this conversion would be appreciated, or where to find a tech article would be appreciated(yes I have searched google without much succes on STOCK HEADS).

Also, is there any down side to removing the hump just inside the exhaust port of the stock head?

FYI, converting from a stock cam to an ISKY Supercam 262, and the stock 2v to a 4bbl Edelbrock 600CFM Carb and Performer manifold.

Thanks, as always.

[Gearhead999]

Any good machine shop can do it.
You have to have the pressed in studs removed.
Then the pedestals have to be machined down. I would check the number but I think it was .250.
Then drill and tap for screw in studs.
Install screw in studs and push rod guide plates and you're there.

[zgreatwhite]

Thanks for the machining info.

the parts for the conversion appear elusive.

At this time, I find Harland Shop rockers fit the bill, 1.6 ratio, for 351W, 3/8 or 7/16 stud.

But, where can I find the studs? ARP makes the studs, ($30), but then state in their catalog you must use their perma-lok adjusters($50)...and then be careful about what size opening you have on your roller rockers.

Trick flow makes a lot of studs, but indicate they are to be used on their heads.

Thanks.

[Rev]

I used 351W heads for several years on my street driven 306. I had them pocket ported and gasket matched with a 3 angle valve job. Even though screw in studs are better, I used the original pressed in studs with Comp Cams Magnum roller tipped (not full roller) 1.6 rail rocker arms (no guide plates needed). I did also use poly-locks to make them adjustable and to hold that adjustment. At that time my engine made about 300 HP and reved to 5500 RPM. The heads worked well on this fairly mild 306 engine.

It wasn't until I went to TFTW heads with a bigger cam and intake that I used the full roller rockers. That's when I felt the need the better valve train. At least, that how I experienced it.

Rev

[zgreatwhite]

Rev...thanks for the info. Sounds like a feasible option.

z

[Gearhead999]

In the Jegs catalog. Crane # 270-99156-16.....3/8
270-99157-16.....7/16