[67Lemons]

Hi, first post here. I just picked up a low mileage 1968 400 out of a Catalina. I’m going to do a basic low budget refresh, tear it down to inspect, replace bearings, rings & gaskets. The motor is untouched so I want to replace the cam, lifters & springs, it has stock #15 heads. It’s going into a 67 LeMans driver, will have a turbo 350 & 3.36 rear gear.

Originally I was thinking a 068 cam but wondering if I should look at a different cam? Maybe a 2801, Crower 06916, etc? The car is a weekend cruiser, might go to the track once or twice for testing.

All the cam failures have me worried but I don’t really have the budget for a roller especially for a low buck garage style build. So what are some best practices for a new cam with today’s parts? Stick with a quality cam mfr, Johnson Hylift lifters, springs from the cam supplier? What else?

[Gach]

The 068, would definitely work for what you want, the thing with cam and lifters and all stuff thats been going on. Just make sure you have someone Who is Competent check lifters for taper and the cam as well. Because thats whats been the issue. With them. The think about going with more cam then 068, is the you get into mostly needed more convertor. In other words the stock convertor you have will work great with 068. And definitely be a good increase in power and torque. Plus with that gear

[dataway]

I had luck going with the same manufacturer for both cam and lifters. I too feel the issue is with lobe taper and lifter crown ... and in my opinion both components from the same manufacture tend to play nice with each other.
In my case Melling and Melling was the solution. Also an affordable solution, and they make a good 068 clone.

[steve25]

You also must tare down the heads and replace the valve seal O rings and confirm that non of the 16 pressed in rocker studs show signs of pulling out.

Also check the studs for gouges where the rockers slots might have worn into them.

Along these same lines it’s good to stick with a stock lift .
( .406” ) so that those 16 pressed in studs stay pressed in and do not snap off where the threads start.

Also check all 16 rockers balls on there flat side for signs of multiple fractures.

That 400 had about 9.6 compression so the 068 is a good cam pick to keep you out of detonation with those iron heads.

You need to add a 60 psi oil pump and new pump drive rod to your shopping list.

[Half-Inch Stud]

068 cam with 1.5:1 will provide good times, highway pulling and great mpg. Any performance above "stock" 068 combos will require an improved fuel delivery: like an electric pusher pump.

But the stock pump will do it all except the 1/4 and 1/8 runs.

[67Lemons]

Thanks for all the fantastic suggestions. I’ll be the one measuring & checking everything, I’m hoping to have as little machine work as possible, mostly for budget reasons but also for the experience of doing it myself. I haven’t built a V8 in 25 years or so & may eventually have a proper built engine done for the car but for now I want to do it for the sake of doing it. I’m strongly considering the Mellings 068 clone with their lifters but all the horror stories have me spooked. Without question I will inspect whoever’s lifters that I purchase for a crown as well as mark the pushrods to make sure that they spin before I fire the motor. I can mic the cam but I’m thinking that we are more concerned about lobe profiles & quality cores correct? I realize that parts today aren’t what they once were, actually I’m a manufacturers representative in the industry so trust me I’ve watched quality sink to the bottom of the barrel over the last 20 years, I’m just trying to put my best foot forward to reduce the likelihood of failure.

I still need a convertor for the 350 so that can be changed for the cam, whatever is streetable is what I’m looking for. A nice tight convertor vs the old school loose sloppy converters that I had in the past, again I want to drive & enjoy the car but want a healthy combo.

[Lee]

The bigger the lift, the greater the chance of failure.

Maybe consider the 744.

[Scarebird]

Originally Posted by 67Lemons

...I want to do it for the sake of doing it...


...I’m just trying to put my best foot forward to reduce the likelihood of failure..

If the donor engine is running fine: no blowby and leakdown test is good, I would just change timing chain and gears, clean it up and run as-is. Aftermarket parts are a crapshoot - your OEM motor if runing well will continue to do so.

[67Lemons]

Originally Posted by Scarebird

If the donor engine is running fine: no blowby and leakdown test is good, I would just change timing chain and gears, clean it up and run as-is. Aftermarket parts are a crapshoot - your OEM motor if runing well will continue to do so.

The motor seems to run great & I’m hoping to get the cylinder leak down test done this week. I’m thinking more along the lines to what you’re saying with all the aftermarket parts issues lately.

https://youtube.com/shorts/tfDFJEQ0E...8cb64KV95NcVUH

[jhein]

Maybe I missed it but are you planning on sticking with the 2 bbl setup?

[Scarebird]

I am wondering if the 1968 and 1970 #15 heads are the same? 1970 shows as 87cc - perfect for today's gas.

Walace Racing shows 1968 small valve 15's as 10.5 to 1 compression for a 2 barrel - not buying it.

[67Lemons]

Originally Posted by jhein

Maybe I missed it but are you planning on sticking with the 2 bbl setup?

Sorry, I should have mentioned that I have a NOS Holley reman quadrajet sitting in a box & currently looking for an OE four barrel intake.

[67Lemons]

Originally Posted by Scarebird

I am wondering if the 1968 and 1970 #15 heads are the same? 1970 shows as 87cc - perfect for today's gas.

Walace Racing shows 1968 small valve 15's as 10.5 to 1 compression for a 2 barrel - not buying it.

Ron’s Pontiac page shows them as two different heads. 75cc for 1968 & 87cc for 1970 455 #15 heads.

[jhein]

With those 75cc heads, would a 744 be a little bit better than the 068 for detonation?

[jamaca85]

i would take the crank down and get it turned, with new bearings it will do very well. if you have the press in stud style heads take the heads down and get the valve job done to them and replace the press on rocker studs with screw in.. the machine shop should be able to thread the holes for you

[Scarebird]

Why tear down a perfectly running engine? Why risk turning a crank that works just fine?

The GTO had a 2 bbl low compression motor; was this not the same with the big cars? Did they not get a regular fuel option?

[Dragncar]

https://www.ebay.com/itm/19191922776...Bk9SR8qj18SUYw

You could put a 30$ timing chain on it and buy a gasket set. Put that 4 barrel carb and intake on and have some fun with it. Save money for a complete rebuild.
Paul K here at one time was re-machining used OEM lifters for the proper crown. Might want to contact him about all this stuff as he does Pontiac engines for a living.
Those re manned lifters with Summit 2801-2802 would run nice.
I have a 76 EGR Q jet intake you could have for free. But the shipping is not cheap these days. Your engine would not know the difference between it and a 67-72 intake.
I also have a complete 400 std bore cast iron set of rings you could also have for free, just pay shipping.
I am not going to use this stuff and I will pass them on to members who can put them to use, just let me know.
Low buck build is perfect.

[HWYSTR455]

What's considered 'low miles'? Do you know for sure the actual miles?

Regardless, an engine that old that's been sitting will need at least some basic stuff, timing chain, clean the oil pan out, a valve job and maybe guides.

Bet it needs a balancer seal. Replacing the water pump sleeve seals is a good idea too, bet they are rotted out. (think cooling issues)

If you're thinking of swapping to a cam outside of what's already in it (profile), you probably need springs too. Shoot, even leaving the cam alone you probably need springs.

If you're having a valve job done, screw in stud upgrade is a good idea, and probably enlarging the pushrod holes is too. You could verify which heads/chambers you have, and more accurately estimate compression ratio.

Does it have acceptable oil psi? Didn't look like you had a gauge on it.

Would be a bummer you get it between the rails, have problems, and just have to pull it out again. A little extra effort now may help avoid more labor and disappointment. I mean it's already out of a car now, makes sense to at least do a look-see.


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[67Lemons]

Originally Posted by Dragncar

https://www.ebay.com/itm/19191922776...Bk9SR8qj18SUYw

You could put a 30$ timing chain on it and buy a gasket set. Put that 4 barrel carb and intake on and have some fun with it. Save money for a complete rebuild.
Paul K here at one time was re-machining used OEM lifters for the proper crown. Might want to contact him about all this stuff as he does Pontiac engines for a living.
Those re manned lifters with Summit 2801-2802 would run nice.
I have a 76 EGR Q jet intake you could have for free. But the shipping is not cheap these days. Your engine would not know the difference between it and a 67-72 intake.
I also have a complete 400 std bore cast iron set of rings you could also have for free, just pay shipping.
I am not going to use this stuff and I will pass them on to members who can put them to use, just let me know.
Low buck build is perfect.

Thank you for the generous offer! I’m currently waiting to hear back from someone that is selling a manifold but I will certainly let you know if not.

Originally Posted by HWYSTR455

What's considered 'low miles'? Do you know for sure the actual miles?

Regardless, an engine that old that's been sitting will need at least some basic stuff, timing chain, clean the oil pan out, a valve job and maybe guides.

Bet it needs a balancer seal. Replacing the water pump sleeve seals is a good idea too, bet they are rotted out. (think cooling issues)

If you're thinking of swapping to a cam outside of what's already in it (profile), you probably need springs too. Shoot, even leaving the cam alone you probably need springs.

If you're having a valve job done, screw in stud upgrade is a good idea, and probably enlarging the pushrod holes is too. You could verify which heads/chambers you have, and more accurately estimate compression ratio.

Does it have acceptable oil psi? Didn't look like you had a gauge on it.

Would be a bummer you get it between the rails, have problems, and just have to pull it out again. A little extra effort now may help avoid more labor and disappointment. I mean it's already out of a car now, makes sense to at least do a look-see.


.

The engine had a little over 40k when removed but your point is well taken. I plan on tearing it down a little further to inspect & replace things accordingly. If I see a reason to get into the bottom end beyond replacing the rope seal or it requires obvious machine work I will send it out to the machine shop but as mentioned above I think if everything looks serviceable I will clean it up & run it. Once I get the heads off I will make a decision on what head work it needs including upgrading to screw in studs or larger valves. Of course with a cam change it will get new springs, keepers, etc.

[HWYSTR455]

I wouldn't crack open the #5 main unless you've already made the decision to take it apart. Most rope seals weep some from sitting for periods of time, but once they get some oil, swell back up and stop leaking.

You can look at like #2 & #4 caps/bearings to get a good enough idea if the mains are good.

One or two rod caps would be fine too, but you should include looking at the bearing half on the rod/piston side to see if there's signs of det.

40k is def low miles, there really shouldn't be any bearing 'wear' unless there was some abnormal condition(s) (such as det). You could toss a psi gauge on there and see what the oil psi is, might not have to crack any caps open. If there's good oil psi, I wouldn't change the bearings.

I wouldn't replace the rings either, in order for them to seat, you need crosshatch in the bore, and you would at least have to do a ball-hone on them. Same mentality on the rings as the bearings, there really shouldn't be any excessive wear.

You can rock the piston some and look down the edge of a piston to the top ring, and if none are cracked or fractured, I say leave it alone.

You would probably see scoring on the walls if a ring was bad, so you can turn it over a few times to get a look at the bores to help make an assessment.

A 2BBL engine shouldn't have seen much abuse, theoretically speaking, but you never know. It looks pretty clean, and does sound pretty good, you might get lucky with just some gaskets/seals and a timing chain (and gears if they are plastic).

I would still pull the pan and clean it out though. Never know what's down there, and you might find clues that will help your assessment.

Not sure I would even change the intake and carb if it all starts looking really good and in your favor. I've seen 350 & 400 2BBL cars run pretty good and changing nothing else but carb/intake to a 4BBL didn't provide much, if any gain.

If you swap the cam, then that's a different story.


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