Hi Everyone,

I recently found a decently priced '69 350 Rocket paired to a long tail 400 trans. From understanding, that long 400 trans won't fit the existing length of drive shaft, so I plan on continuing to use the existing transmission that's in the car. My main question is, should plan on having to run some sort of lead substitute in this motor, since it's from '69?

 

I would also run the trans that is currently in your car and not use the long shaft. No need for a lead substitute.

 

+1.

That 350 was originally bolted to a TH350. Keep the TH400, because you never know when you'll need one.

And, like Eric says, no need for lead.

Just bolt that sucker in and drive.
Be sure to use the brackets and pulleys from the engine that's in your car.
If the fuel pump on the replacement only has 2 nipples, use the fuel pump from the old engine.

If it's a high compression motor (originally had a 4bbl carb), you'll need to run the highest grade Premium you can get (if everything is clean inside, 93 should do it), and may need to add an octane booster, or to retard the timing slightly, especially since that '77 probably has a very tall rear end ratio.
If you do need an octane booster, Octane Supreme works great, because it's got actual tetraethyl lead (the lead, in this case, to increase your octane, even though you don't really need it for your valves).

- Eric

 

Either above or add Felpro head gaskets and maybe a slightly larger cam. The factory cam is tiny but will work well with tall gears.

 

One good thing is that with gas prices so cheap you can run premium for a lot less now. I'd also change out the rear gears to something like 3.23 or 3.42:1 or shorter. That would be one bad mama off the line. If your TH350 needs freshening or overbuilt this is the time to do it.

 

Awesome everyone, thank you for the replies, I was hoping I wouldn't have to rub a lead sub to drive the car. The '69 engine is out of a Delta 88, and it has a two barrel carb only. Kinda throwing around the idea of swapping the intake from the '77 onto this, and continuing to use a 4barrel.. Any idea about that simple swap?


Also, with the '69 currently sitting in an engine stand, I was thinking about just going through and replacing gaskets, specifically value cover ad oil pan gaskets. Anything else I should address while the engine is really really easy to work on? The '69 has sat for a number of years, but did fire right on in a test bed.

 

Timing set, Clean out oil galleries, check bearing shells, clean and paint outside, check oil pump and screen, clean out coolant passages between cylinders as much as you can...

- Eric

 

Not trying the threadjack, but could you describe more what you mean about cleaning out the oil galleries? I have my motor out on the stand with the intake off right now and MAW.

 

Not threadjacked at all, I was wondering the same thing when I read that.

The previous owner mentioned attending to a cork seal that's visible once the oilpan is off, and to replacement that to avoid any headaches once it's mounted. Any idea what cork seal that is?

 

Disassemble motor, remove oil gallery end plugs, use long-reach bottle brushes to clear galleries and branches, use a strong detergent, flush with lots of water, blow out with compressed air, and dry machined surfaces well and coat with oil or WD-40.

- Eric

 

Ah, thank you for the clarification. Is there a known gold paint that matches the stock color that's easily available?

Might just be time to get that done too... Might be spending the quartly bonus from work a bit early

 

This is a very frequently asked question.
You will find threads on this subject here, here, here, here, here, here, here, here, and here, for starters.

- Eric

 

Perfect, you will be sitting around 9 to 1 compression, pretty sure there wasn't a high compression 2bbl option for the 350. Do all the gaskets except head gaskets, if the antifreeze looks good, including the rear main seal with a rubber replacement. As said a good clean up and timing set, get something like a Cloyes double roller and seriously consider a mild cam swap, Cutlassefi is a good source. Your 4bbl will swap right over, might be slightly lean but close enough. I like the factory "turkey" tray" intake gasket, especially with an iron intake.

 

Thank you very much, search is very helpful, but not helpful when not used


Excellent, thank you for the information. Why do you advice against touching the head gaskets? I figured I'd go as deep as I could, just since the engine is out on the stand, and much more accessible. I'm curious to see the condition of the pistons and cylinder walls, and for peace of mind having new head gaskets in place.

 

That's okay. The Search function here sux anyway. If you google ClassicOldsmobile.com <space> Whatever you're looking for, you can do alright, though.


Because the original head gaskets are 0.016" steel shims, and are getting difficult and expensive to find, and if you use the commonly available replacements, which are about 0.042", you will lose about half a point of compression.
There are almost-as-thin fancy racing gaskets, and a few OEM gaskets floating around, or you can have the heads milled to use the Fel-Pros.

- Eric

 

Ah, thank you for the clarification! I was just thinking about nabbing this complete gasket set off of RockAuto, but I'll avoid the headgaskets in that kit.

http://www.rockauto.com/catalog/more...nid=494&jpid=2

Do you know of any gasket kits that still sell the stock 0.016" head gaskets?

 

DUPLICOLOR Universal Gold at NAPA.

P5140020.jpg

 

my thought is change the head gaskets. Like has been said they steel shim gaskets and it is from '69 and they do rust out. May be ok for the moment, but down the road may have a blown head gasket. You will have to use the fel pro gaskets or you can get the special MLS head gasket for $$$.
I would use the fel pro gasket and mill .035 off the head. The engine is out and right in front of you, or lean over the fenders later.
just my opinion .

Gene

 

Contact Smitty from M&J Proformance. He sells .011" shim head gaskets, not cheap, around $120 a set, I think. If the antifreeze comes out looking decent, the originals are probably fine. If there is brown rust sludge, change the head gaskets. I changed them on a 76 350 with really ugly coolant, they were leaking. Next one was fine, nice clean coolant.

 

I agree, I feel like removing the heads and ensuring a straight edge and milling the heads might save me any additional work a few miles/years down the road. The coolant wasn't exactly the greatest color when it was drained.. I spoke to a local shop that machines heads, and they quoted $130 to mill and check the heads for cracks. I figure the peace of mind of a straight edge and milling would be better than just buying the expensive exact replacements.

My main question though, is .035 the exact amount needed to mill to use the fel-pros and not negatively affect compression? I don't want to shave off too much, or too little.

 

Felpro's are .041" thick vs .017" thick for factory head gaskets. Get .025" milled off and you are good. I hope you are upgrading the pathetic factory cam after doing all this work.

 

Milling each 0.005"-0.006" will remove about 1cc of combustion chamber volume.

If you take off 0.035" and use a head gasket that's 0.035" thicker, then you have just gone back to where you started, and have actually changed nothing.
You can confirm the thickness of the old gasket when you disassemble the engine, and check the compressed thickness spec. of the new gasket, and just do the math and feel confident - It should be about 0.025", and a couple of thousandths one way or the other aren't important.

If you do confirm that you have the low compression pistons when you remove the heads, you also have the choice to remove a little bit more than 0.035", and increase the compression a bit. Taking an extra 0.020" will decrease volume by about 20cc, which will increase compression by about a quarter point, an extra 0.040" will give you about an extra half a point (but you'll have to confirm that your lifter preload is still in the correct range when you reassemble).

- Eric

 

Thank you. I am planning on upgrading the stock cam after all this work, but one step at a time. I found this thread:

https://classicoldsmobile.com/forums...-camshaft.html

Where a Erson Viking 100H was recommended by cuttlassefi. Might go that route after some further investigation. From what I gather cuttlassefi is the guy to talk to regarding cam swaps.

Thank you. I plan on removing the heads tonight after work. I'll measure the existing gaskets at that time and check the pistons, I'm guessing they're low compression, with the stock 2barrel intake still on the engine, and the engine being untouched from what I can tell from how far I've gotten into it. I wouldn't mind getting a bit more milled off for a tad more compression, but I don't want to get too close, and be forced to go to high octane.

 

Go with Mark's(Cutlassefi's) recommendation. If you mill the heads too much, your intake will also need milling. The factory style "turkey" tray intake gasket works best with milled heads or less than straight Edelbrock intake manifolds. The Mr Gasket Ultra seal and SCE fiber gaskets are good but much thicker than the factory style stainless intake gaskets.

 

Hey everyone,

Just a quick update, spent some time in the garage getting the intake and heads pulled, glad I decided to do so. It appears the head gasket on cylinder 3 was leaking, as you can see from the buildup. The coolant that came out wasn't terrible, but the oil color was less than desirable.

Other than that, the cylinder walls were in excellent condition, and the valves appear to still be pretty solid. Please see the collection pictures below:

http://imgur.com/a/yjlVi

 

At least it wasn't all gummed up. Did you pull the pan and clean out all the plastic bits from the timing set?

 

Pan has been pulled, the sump looked clean, not gummed up or anything. As far as the timing set, it doesn't have a nylon gear, and it was pretty clean inside. I plan on cleaning much more thoroughly both in and out prior to paint though.

 

I saw it already had an aftermarket timing set on it, that also needs to be replaced. But you never know if the plastic was all cleaned out when they replaced it originally. I'd also pop the lifters out one by one and inspect the cam lobes and lifter bottoms for wear.

 

Yep, definitely replacing the timing chain, as there's some significant slack on each side. I'll dig through it and get rid of any plastic I can see. I'm planning on swapping the cam for something a little more oomph, although I'm still torn between what I want, given the stock gears in the rear end, don't want to go down the wrong path. The Delta 88 the motor was removed from had 77k on the odometer, so I was a tad surprised to see the timing set had already been replaced at some point in the past, but maybe the stock timing chains had less longevity back then..