[flat-bill]

I am working with a '56 block and I will be using '59 heads. These are stud oiled heads. If I use a new cam and lifters I suspect that the lifters will be set up for pushrod oiling. Should I just use the later pushrods and plug the stud oiling? I expect that I could plug the oil passages at the block. Are roller rockers available for these early studs or should I convert to the typical 7/16 style studs? Anything else I should know about this head swap?

I am replacing an earlier build that got wet and I am thinking that when I pull it apart I will find a freeze cracked block. When I drained the pan water came out first, then the oil. It has forged JE pistons and I want to reuse them. This setup will have a '57 tripower and a mild cam in a 2700 pound sedan for street use with an overdrive trans and a 3.42 rear end. Thanks, Billk

[Bill Hanlon]

It's not the lifters that determine if stud oiling works, it's a combination of the cam (is it properly drilled in the #2 and #4 journals?), the cam bearings (corresponding oil holes to cam?) and the rocker balls (do they have a partial larger diameter bore that lines up with the stud's oil hole?). Finding the proper rockers & balls used to be real hard, but some company in NJ (Falcon?) is now making them. Kanter sells them. All you need is $$$.

[Jack Gifford]

Originally Posted by flat-bill

... Should I just use the later pushrods...
... and plug the stud oiling?
... Are roller rockers available for these early studs...
... should I convert to the typical 7/16 style studs?
... Anything else I should know about this head swap?

As Bill said, it's not the lifters and pushrods that determine how rockers get oiled. I'm 99% certain the '56 pushrods are tubular, just like all later ones. For the pushrod oiling to function, you need rocker arms with the 'spurt' hole at the pushrod socket. I've used such rockers long ago, but unfortunately I don't remember the source.

Defeating stud oiling is never required, even if you change to through-the-pushrod-and-rocker system.

Roller rockers aren't generally available for the early heads ('55 through at least '59, maybe also '60). Not because of stud size, but the rocker itself is a totally different profile from later Pontiac rockers arms. [H-S SBC roller rockers are close and I used them on a '58, but unless you're a machinist, I don't advise it].

There's no reason for you to convert to "typical 7/16 style" studs (they're only 'typical' for later Pontiacs).

Have you figured out where the compression ratio will be with '59 heads on a '56 shortblock with your "reusable" J-E pistons?

[flat-bill]

The forged JE pistons have about 5000 street miles on them. They were installed with chrome rings in 1965. They are suppposed to be 11:1 with the '56 heads. They are 1/8 inch oversize, at 4.062". They have a popup on the top. My plan is to measure the '59 heads and cut the dome down to get to 9:1 compression. A rough measurement of the '59 heads ( I don't really trust this ) shows about 80 cc's. I have not yet disassembled the motor to see if the piston domes are "solid" or hollow.

In '65 the motor ran very well on premium gas and pulled the '33 Chevy sedan along smartly with the 4.11 '54 Pontiac rear end and '57 Chevy 3 speed trans. I used a '58 factory bellhousing and 11 inch flywheel and clutch.

I got the car in late '64, built the motor in '65 and drove the car for a year before going into the Air Force. I've been dragging it around since then. Its time to rebuld the whole thing now and have some fun. Billk

[flat-bill]

Jack said "[H-S SBC roller rockers are close and I used them on a '58, but unless you're a machinist, I don't advise it]."

I am a machinist. What is required to modify them. If I get a set of them will it be fairly obvious what to do?

[Jack Gifford]

'59 heads definitely weren't 80 cc; somewhere around 67/68 cc I think.
You could do as I did- borrow a SBC roller rocker and play around with it on one of your '59 heads. Looking at a cross-section (end view), decide if there's any combination of valve stem length and rocker trunnion location that gives correct geometry (a line through roller and trunnion centers is perpendicular to valve stem centerline at about mid-lift). In my case, this left the trunnion center only slightly offset from the original stud centers. I placed aftermarket studs (7/16" tops to match the rockers, and 1/2-13 base threads) in the required location by working on the heads in the mill- first milling tops of stud bosses flat (needed for stud shoulder seating), then plunge-milling/drilling/tapping for the studs (difference between original 3/8" stud holes and the 1/2 studs accomodated the slight offset okay). Valves with custom length came from Ferrea (but were "catalog" items, as I recall). As the engine went together, I determined pushrod length during valvetrain mockup and bought custom-length pushrods.

[flat-bill]

Jack, You're right, the upgrade to the roller rockers is a machinist's job. I will try to scare up an SBC rocker and check it out. I think I can do the modifications. When you did it I suppose you went to pushrod oiling.

I can see that working with this early stuff is more "interesting".

Thanks for taking the time to help me out. Billk

[Teej]

From Safari Larrys page: http://www.pontiacsafari.com/L1Early...nes/index.html

All '59 heads were either 68.6 or 74.7 cc.
1956 Heads were 69.6 with the exception of the 2-4bbl option and those were 58 cc.

[flat-bill]

Teej, That's a lot of great info. Thanks. Billk