[phoenixpnr]

Though familiar with Pontiac, I am new to the pre 59 Pontiac engines. I've read some of the other threads about them but would like some input on modifications.

I plan on prepping the crank and having it nitrided
The rods will get the normal upgrades like polish and ARP bolts and proper heat treating
Piston availability is lean, the only ones that I have found are cast units on the bay
I plan on using a solid flat tappet cam newer style push rods and roller rockers

I was planning on converting the press studs to a chevy style 7/16 screw in stud and adding guide plates, does any one have a style of stud that they recommend?

As far as oil pumps, I got the feeling that the floating style pick-up was not too god for perf usage. I read the thread on early oil pumps and haven't decided weather to go with the early style or try to modify the later style.

Any other insights or known problems would be greatly appreciated!
Thanks!!

[Steve Barcak]

Originally Posted by phoenixpnr

Though familiar with Pontiac, I am new to the pre 59 Pontiac engines. I've read some of the other threads about them but would like some input on modifications.

I plan on prepping the crank and having it nitrided
The rods will get the normal upgrades like polish and ARP bolts and proper heat treating
Piston availability is lean, the only ones that I have found are cast units on the bay
I plan on using a solid flat tappet cam newer style push rods and roller rockers

I was planning on converting the press studs to a chevy style 7/16 screw in stud and adding guide plates, does any one have a style of stud that they recommend?

As far as oil pumps, I got the feeling that the floating style pick-up was not too god for perf usage. I read the thread on early oil pumps and haven't decided weather to go with the early style or try to modify the later style.

Any other insights or known problems would be greatly appreciated!
Thanks!!

Back in the 70's timeframe, the 58-62 rods were considered worth putting money into for performance useage. Since then, we have learned they are not the hot setup. At least, switch to the mid 60s and later cast rods or upgrade to an aftermarket.
On pistons/rings. The 370 has the same bore as the 389 so, you can use those rings.
On pistons, you may end up having to buy/order a custom piston.
You could also use a more common 389/400 forged piston and use a longer than stock rod. There are lots of options. Depending on the build and what level of power you desire. The block and crank are among the strongest production peices Pontiac evern offered so, the potential is endless. Any head will both to your block too so, the sky is the limit.
Good luck with your build.

[blueghoast]

Originally Posted by Steve Barcak

Back in the 70's timeframe, the 58-62 rods were considered worth putting money into for performance useage. Since then, we have learned they are not the hot setup. At least, switch to the mid 60s and later cast rods or upgrade to an aftermarket.
On pistons/rings. The 370 has the same bore as the 389 so, you can use those rings.
On pistons, you may end up having to buy/order a custom piston.
You could also use a more common 389/400 forged piston and use a longer than stock rod. There are lots of options. Depending on the build and what level of power you desire. The block and crank are among the strongest production peices Pontiac evern offered so, the potential is endless. Any head will both to your block too so, the sky is the limit.
Good luck with your build.

Steve can you bore a 347 that far?
I've got a 57 that I want to rebuild also, Isn't the bore smaller?

GT.

[phoenixpnr]

I have a friend that takes older components (head, timing cover, etc.) and puts them on 350s and 400s. Everything is easy then, late bellhousings and auto trannys are a direct fit, but that's not what I'm looking to do.
Keeping in mind that I'm not setting up an ultimate race engine, I was trying to use as much of the original 347 components. I am planning on using this in a "hot rod", so I want it to "look" like a 57 347- with the old heads and water inlets to the timing cover. I know the 57 rods aren't that great, but they will be fine for the power this build will produce.
Besides the cost of heat treating, how will the 63+ cast rods be better then the 57 rods?
I have found a 1.94 intake valve that is the correct length, coupled with good port work, the 347 heads will work fine.

[phoenixpnr]

Originally Posted by blueghoast

Steve can you bore a 347 that far?
I've got a 57 that I want to rebuild also, Isn't the bore smaller?

GT.

I think he was suggesting to go with a 370 instead. Compelling reasons, but I'm sticking with my 347.

[Steve Barcak]

Originally Posted by blueghoast

Steve can you bore a 347 that far?
I've got a 57 that I want to rebuild also, Isn't the bore smaller?

GT.

My mistake. did not mean to confuse or misinform. I was thinking of the bore on a 370 and his is a 347. Sorry about that.

Yes, the bore is smaller on a 347 than a 370. They do share the same stroke.

Not sure how far a 347 could be bored. Others here may know. You could sonic check it to know for sure.

[Steve Barcak]

Originally Posted by phoenixpnr

I think he was suggesting to go with a 370 instead. Compelling reasons, but I'm sticking with my 347.

Yes, sorry about that. on the confusing a 347 with a 370.

Also, when you referred to performance useage, that can mean most anything and I did not know how serious of an engine you wanted.
Best to you.

[blueghoast]

I rebuilt a 347 for a guy for his 57 pontiac that had just been rebuilt.
A chevy guy did the rebuild and it took the cam out almost immedietly.
The rocker arm geometry was a mess with chevy stuff. I straiten out
the heads and got the geometry correct and freshened the rest.
A lot of the work look really nice like the port work and the short block.
It has ross pistons and polished rod the crank had been cleaned up and
machined. It is a 10:0:1 motor can't remember if 30 or 60 over It's been
a while. The cam I used is a smaller one don't remember specks off hand.
When I took it out for the test drive I was shocked at the performence
level of this car would give a stock mustang a run for the money and the
customer was very happy how well the car run and performed too. I ended
up useing Harland Sharpe rockers. The 347 cu. is a pretty stong perfomer
If you want to go with it. When I get to my 57-wagon I'm going to copy
that build as it impressed me how well it runs overall.

GT.

[Jack Gifford]

Originally Posted by phoenixpnr

1>... ARP bolts
2> ...proper heat treating
3> ...newer style push rods
4> ...roller rockers
5> ...adding guide plates
6> ...early oil pumps ... or try to modify the later style

First of all- if you'll be using later than '60 heads, ignore this post.
Secondly- feel free to label me a 'know-it-all' and ignore this post on general principle.

1> Last I knew, ARP was still making bolts for the early ('55-'62) rods, but they were getting hard to find. Don't be tempted to use the the more common later Pontiac ARP bolts.
2> I'm not aware of any possible strength improvement to cast '57 rods by heat treating (cryogenic treatment could help somewhat). If you're thinking of heat treating forged '58-'62 rods, that can also be problematic- some literature says they were SAE 1139 alloy while other sources say 1140.
3> I'm assuming you're referring to delivering all top-end oil through the pushrods. Just to clarify terminology- your '57 pushrods are the same "style" as later (and work fine to deliver oil). The "style" change to oiling requires rocker arms with oil holes at the pushrod socket.
4> I'm not aware of any "bolt on" roller rocker arms being available for '55-'60 heads (whose valve trains have different geometry from later heads).
5> Guide plates can't simply be "added", since early pushrods are guided by the holes in the heads. I know of no reason to change this scheme anyway.
6> All the pumps are of the same "style" (rotors and shaft can even be interchanged late-to-early). The main difference is that '55-'58 pump main bodies were slightly different layout, due to the smaller than 3" rear main caps. Another difference was the 5/8" diameter pickup tube (not a problem for under 500 HP).

[phoenixpnr]

Originally Posted by Jack Gifford

First of all- if you'll be using later than '60 heads, ignore this post.
Secondly- feel free to label me a 'know-it-all' and ignore this post on general principle.

1> Last I knew, ARP was still making bolts for the early ('55-'62) rods, but they were getting hard to find. Don't be tempted to use the the more common later Pontiac ARP bolts.
2> I'm not aware of any possible strength improvement to cast '57 rods by heat treating (cryogenic treatment could help somewhat). If you're thinking of heat treating forged '58-'62 rods, that can also be problematic- some literature says they were SAE 1139 alloy while other sources say 1140.
3> I'm assuming you're referring to delivering all top-end oil through the pushrods. Just to clarify terminology- your '57 pushrods are the same "style" as later (and work fine to deliver oil). The "style" change to oiling requires rocker arms with oil holes at the pushrod socket.
4> I'm not aware of any "bolt on" roller rocker arms being available for '55-'60 heads (whose valve trains have different geometry from later heads).
5> Guide plates can't simply be "added", since early pushrods are guided by the holes in the heads. I know of no reason to change this scheme anyway.
6> All the pumps are of the same "style" (rotors and shaft can even be interchanged late-to-early). The main difference is that '55-'58 pump main bodies were slightly different layout, due to the smaller than 3" rear main caps. Another difference was the 5/8" diameter pickup tube (not a problem for under 500 HP).

I won't say a know it all, at least not out loud.
I haven't had a problem finding the correct rod bolts for fair prices.
I "assumed" the pre 58 rods needed to be heat treated like the later ones. I was going to do a molten salt bath treatment. Are the 57 rods OK to use period? I have plenty of other options otherwise.
I had planned on pulling the press studs, cutting down the bosses and going with a 7/16 RA IV style rocker stud. I am also going to have to open up the push rod tubes for room for a decent lift cam and also so that there isn't an interference between those and the guide plates that I plan on running (held down with rocker studs).
I haven't compared them yet, but are the distances from the rocker fulcrum to the valve tip and the push rod cup different then later styles?
I had seen in another thread that the floating style pickup was problematic on hard acceleration? The main body cast looks so much spindlier then that later units, is there any strength issue there?

[Jack Gifford]

Originally Posted by phoenixpnr

... are the distances from the rocker fulcrum to the valve tip and the push rod cup different then later styles?...

Yes, they're different. SBC rockers are close to being 'right' for early Pontiac. I used Harland-Sharp SBC roller rockers on my last '58 build, by carefully relocating the studs and using custom-length valves and pushrods [details are in a post somewhere on this forum].

When I sit the oil pumps side-by-side I don't see any glaring difference. I never had any problem with an early pump, even in 500 HP alky-injected competition engine-to 7,200 RPM for many seasons of mini-rod pulling.

I don't personally like the floating pickup. And the only reason Pontiac used it was to keep the pickup out of any sludge accumulated on the bottom of the pan (remember that in '55 detergent oils were still fairly new).

[phoenixpnr]

I haven't looked at the pump yet, but I wonder if I can open up the pick up opening and press a newer style one in instead of using the floater?