[John62]

Thanks all, Bart I have read your build, a couple times trying to learn the little details that mean a lot. Is a new harmonic balancer a must. It may need guide plates because the ticking sound it was making was a rocker arm turned enough to push on the valve top cup a bit and not just the valve head. Bart I did get a bit confused when you said I think page 7 you may go with just stainless valves and not seats so is just stainless valves an option or are they needed with hardened seats? Do stock rods ever fail on a stock build, new rods while nice seem like overkill. All the rods and bearings were in nice shape.

[hurryinhoosier62]

Originally Posted by John62

Thanks all, Bart I have read your build, a couple times trying to learn the little details that mean a lot. Is a new harmonic balancer a must. It may need guide plates because the ticking sound it was making was a rocker arm turned enough to push on the valve top cup a bit and not just the valve head. Bart I did get a bit confused when you said I think page 7 you may go with just stainless valves and not seats so is just stainless valves an option or are they needed with hardened seats? Do stock rods ever fail on a stock build, new rods while nice seem like overkill. All the rods and bearings were in nice shape.

John, your friend could get lucky and never have problems with properly prepared stock cast steel rods, but is it worth the cost IF the stock rods fail? Back in the "old" days, we made due with the stock rods because we had VERY limited choices. You could track down the '59-62 "rubber" rods, have them properly heat treated and prepare them, attempt to find the SD455 rods, or go with Carillo rods ($1,500 a set in 1986). With the affordability of the current forged rods, prepping a set of stock rods doesn't make a lot of sense UNLESS you are forced to (i.e., NHRA Stock class). The problem with stock rods is you have no idea how many cycles they've endured. All internal engine components have a cycle life. Exceed the cycle life and you WILL pay. IMO, a new balancer goes hand-in-hand with an engine overhaul.

[John62]

My understanding is new rods will require the same prep work as original rods. Is there any real savings there other than they are new verus old. I will push for them and a new balancer. He is suppose to get a new parts breakdown today, I will try to post it when I get my hands on it.

[geeteeohguy]

IME, with an o68 cam, you will be fine with your stock rocker studs. No need for guidplates, either. But I would upgrade the rods. Only a bit more than reconditioning the old rods, which needs to be done anyway. And the new rods need to be checked out by a good machinist....they are not a bolt in and run deal.

[rexs73gto]

With our junk gas today you should always get new forged pistons as they will get beat to death & fail if you don't. Guide plate because they are so cheap are just good insurance. Your going to a bigger lift cam so you need to make sure they are going up & down correctly. Also you need to install hardened seats or you'll be pulling the heads in another 10,000 miles to freshen them up AGAIN. If you go with the Eagle H-beam rod ,,, forged you will get quality bolts in them. Then to ensure that all parts are working together use forged pistons, you can get some as low as $ 300.00 a set (TRW) & the are just fine for a stick build. I run them in my 413 build & it turn 6500 a lot when I'm on the track & sometimes else where to. LOL. A new balancer is a no brainer. Then of course you need screw in studs or the new cam with the new pressures will most likely pull out some or all the push in studs. Then for the last it will be a must to have the assy. balanced so it all goes around in a nice smooth rotation. Balancing is not that expensive. Around here I get mine done for $ 250.00 & thats to + or - 2.5 grams. If you go closer it will cost a little bit more. But this will keep it together if you ever happen to miss a gear or it slips into N for some unknown reason. Roller lifter are nice but that will cost you an extra $ 1200.00 to $ 1500.00 depending on the brands you get. Going roller you will need roller lifters, new shorter push rods, & roller rockers, which won't fit under the 65 valve covers unless you use the valve cover spacers which add an additional $ 100.00 or so. Then you have all the reg. parts rings, bearings , rear main seal, which the 1 piece is the best IMO. New cam bearings, & all the gaskets to put it back together. In your statement you want a stock build, well there really is no such thing as a stock build anymore if you want it to stay together. Please spend the extra money & save yourself a LOT of headache in the long run.

[John62]

Lots of good advice here, keep it coming. I will be out of town till Sunday night so I will check back in then. Thanks all.

[gtofreek]

Originally Posted by John62

Thanks all, Bart I have read your build, a couple times trying to learn the little details that mean a lot. Is a new harmonic balancer a must. It may need guide plates because the ticking sound it was making was a rocker arm turned enough to push on the valve top cup a bit and not just the valve head. Bart I did get a bit confused when you said I think page 7 you may go with just stainless valves and not seats so is just stainless valves an option or are they needed with hardened seats? Do stock rods ever fail on a stock build, new rods while nice seem like overkill. All the rods and bearings were in nice shape.

Stock rods used to fail in stock engines back when they were brand new, so yes, stock rods do fail in stock builds. Only difference now is the rods have millions of cycles on them. Does your buddy want to rick a several thousand $ engine build over a set of $400 rods? If a stock rod fails, the engine will most likely be complete junk afterwards.

I did the math once for the cycles of a rod in an engine that was cruising at 2000 RPM for 100,000 miles. It was something like 6-7 million cycles. Food for thought.

[geeteeohguy]

Thanks for that, Paul. The stock rods have been pumping up and down in my '67 GTO for 250,000 miles....or 18 million cycles. Yikes. When I rebuilt it in 1988, there were no affordable aftermarket ones. Now I have something else to keep me up at night, along with wondering when the crankshaft in my Model T is going to break in two!

[gtofreek]

I look at steel rods as a $400 life insurance policy for your multi thousand dollar engine. Cheap insurance.

Plus, if the guy puts tri-power on it, you just know he's going to put his foot in it! Who could NOT put their foot into it with a tri-power 389!

[b-man]

Originally Posted by geeteeohguy

IME, with an o68 cam, you will be fine with your stock rocker studs. No need for guidplates, either. But I would upgrade the rods. Only a bit more than reconditioning the old rods, which needs to be done anyway. And the new rods need to be checked out by a good machinist....they are not a bolt in and run deal.

Maybe, maybe not.

The stock press-in studs can pull even with somewhat mild stock cams. Using the performance ability of a GTO 389 may well cause the studs to back out, why risk it?

Guideplates not needed if using a low-lift stock cam, the heads already have pushrod guide slots machined into them. If the guide slots in the heads are worn out you'll need to install guideplates.

[hurryinhoosier62]

Originally Posted by gtofreek

Stock rods used to fail in stock engines back when they were brand new, so yes, stock rods do fail in stock builds. Only difference now is the rods have millions of cycles on them. Does your buddy want to rick a several thousand $ engine build over a set of $400 rods? If a stock rod fails, the engine will most likely be complete junk afterwards.

I did the math once for the cycles of a rod in an engine that was cruising at 2000 RPM for 100,000 miles. It was something like 6-7 million cycles. Food for thought.

Excellent post, Paul. A friend of mine died when the rod bolts in the aircraft engine he had just overhauled failed. The bolts passed NDT and stretch, but no one can see the intergranular corrosion that takes place on the molecular level. In our Pontiacs, forged rods are cheap insurance.

[rexs73gto]

I would NEVER tell anyone not to use guide plate in any engine with miles on it. The amount of ware in any engine with 100+ ths miles needs guide plate as much as good rods to keep everything in line. Plus why would you spend $ 400.00 on a set of steal rods when you can buy a good set of forged H-beam rods for the same amount. Eagle H-beam forged rods are only $ 425.00. No reason not to use them ever. Also guide plates are a very small amount of money when it comes to an engine rebuild. Guide plate from just about any Mgf. only run about $ 35.00 for the set. Any one can put them in as they just bolt right under the screw in studs. Easy-peasy.

[hurryinhoosier62]

Originally Posted by rexs73gto

I would NEVER tell anyone not to use guide plate in any engine with miles on it. The amount of ware in any engine with 100+ ths miles needs guide plate as much as good rods to keep everything in line. Plus why would you spend $ 400.00 on a set of steal rods when you can buy a good set of forged H-beam rods for the same amount. Eagle H-beam forged rods are only $ 425.00. No reason not to use them ever. Also guide plates are a very small amount of money when it comes to an engine rebuild. Guide plate from just about any Mgf. only run about $ 35.00 for the set. Any one can put them in as they just bolt right under the screw in studs. Easy-peasy.

Excellent points, Rex.

[gtofreek]

Originally Posted by rexs73gto

I would NEVER tell anyone not to use guide plate in any engine with miles on it. The amount of ware in any engine with 100+ ths miles needs guide plate as much as good rods to keep everything in line. Plus why would you spend $ 400.00 on a set of steal rods when you can buy a good set of forged H-beam rods for the same amount. Eagle H-beam forged rods are only $ 425.00. No reason not to use them ever. Also guide plates are a very small amount of money when it comes to an engine rebuild. Guide plate from just about any Mgf. only run about $ 35.00 for the set. Any one can put them in as they just bolt right under the screw in studs. Easy-peasy.

Are H-beam rods NOT steel? When I posted $400 for a set of steel rods, I was talking about H-beam, as the RPM I-beams are on factory backorder, and are under $300.

It's not just a matter of bolting on guideplates. You also need to drill the guide holes in the heads out.

Also, OP mentioned one of the rockers was sitting on the retainer, which leads me to believe that the guide holes in the heads are worn out, making guideplates necessary.

[John62]

Originally Posted by gtofreek

I look at steel rods as a $400 life insurance policy for your multi thousand dollar engine. Cheap insurance.

Plus, if the guy puts tri-power on it, you just know he's going to put his foot in it! Who could NOT put their foot into it with a tri-power 389!

Funny you would mention that. He did put a tri power on it a few years ago, mostly for the looks but no one can avoid putting there foot on it once in a while. So, at this point what rods should I tell him to go with, and what guide plates. The shop said just by guessing at this point, looking like .030 over not measuring yet, its in the cleaning tank so what is a good brand choice for pistons that can be bought in assorted dish sizes, in this case maybe about 20cc. As far as the heads, they were not cleaned up yet but do they originally come with valve seats as part of the head and he needs to machine a spot to install hardened seats or are there removable/replaceable seats in there now from the factory and how does stainless steel valves play into the equation. Thanks all for all this help.

[b-man]

The only guideplates that will work with the '66 and earlier 389/421 heads are the adjustable plates made by both ISKY and Comp Cams.

The later factory guideplates can likely be cobbled-up to work, but more work than it's worth.

In any case, the guide bosses need to be cut down by .250" to make room for the guideplates and the bottom hex portion of the new studs not to mention to give the studs something flat to seat on.

As Paul already pointed out, the guide slots in the heads need to be drilled out so they don't 'fight' the new guideplates. There's a pretty fair amount of machine work and parts cost involved to add screw-in studs and guideplates to these earlier Pontiac heads. Don't forget that stock pushrods for the early heads are not hardened, in order for the pushrods to be compatible with the new guideplates they must be replaced with hardened ones.

[gtofreek]

Originally Posted by John62

Funny you would mention that. He did put a tri power on it a few years ago, mostly for the looks but no one can avoid putting there foot on it once in a while. So, at this point what rods should I tell him to go with, and what guide plates. The shop said just by guessing at this point, looking like .030 over not measuring yet, its in the cleaning tank so what is a good brand choice for pistons that can be bought in assorted dish sizes, in this case maybe about 20cc. As far as the heads, they were not cleaned up yet but do they originally come with valve seats as part of the head and he needs to machine a spot to install hardened seats or are there removable/replaceable seats in there now from the factory and how does stainless steel valves play into the equation. Thanks all for all this help.

Unfortunately, since not many 389's are being built these days, they are not a lot of piston choices for them. Basically you have 4 choices from what I can find.

1. Sealed Power stock replacement cast pistons. They use stock rings, and come in standard oversizes. These are flat top pistons that will give around 10:1 compression.

2. KB Hypereutectic pistons. These are flat top also, and are suseptable to breaking the top of the pistons off if the engine detonates. They require a lot of top ring end gap.

3. DSS racing pistons makes a flat top forged piston. Butler sells them. They make them for E-heads or later iron heads, or for early 389 type heads.

4. Custom. then you can get them made with whatever dish you want to get the compression where you need it, and whatever rings you want so you can get away from the tractor rings the factory used!

As far as rods go. There are several choices. If $'s are a concern, RPM H-beams are about the least expensive. Eagles are good, as well as SCAT, and others, but they will be more $'s also. Kauffman Racing Equipment has a decently priced Warrior H-beam rod also for around $400.

20 CC's seems like a lot of dish for a 389. I'd have to do some calculations, but I'm thinking more like 10 cc's or so.

[tom s]

Paul,for a true stock type budget build,Egge makes a correct cast piston for the early valve angle heads.I used a set in my 4 cyc rebuild.Tom

[gtofreek]

Sealed Power makes a cast piston also. I just recently built a stock 1964 389, 4 bbl. with them. It ended up right at 10:1. We used a 227/227 @ .050" VooDoo HFT cam in it. It did not ping on 91 octane on the dyno. But there are not many options when it comes to forged pistons for the 389.

[tom s]

I did not have to worry,factory 8 to 1 engine.Tom