I'm in a quandry. Nothing wrong with my Cutlass. The 350 4V is strong, even with 119000 miles and the TH350 is just as good with one rebuild back about 30000 ago. Original axle is a 2:73 so it gets reasonable performance and mpg. Don't care about that anymore since its not just a driver anymore.

I can get a complete (1969) 400/400 or a complete (1971/2) 455/TH400 for rebuild for a reasonable price. Which is the best way to go? 400 (possibly overbored to 425) or 455 which I know the car could have been ordered with?

I'm keeping the original motor and tranny, but I really want a bigger power plant in my car. I've already ordered a new posi carrier and ring/pinion 3:42 gear set.

 

Go with the 455 more hp torque. Same size and just a little more weight. It bolts in the same place as your 350

 

455

 

455 It makes all the diff in the world

 

Since you already purchase a new rear end for it why don't you install that first and then see how you like it? 2.73s to 3.42s is a big switch. Even with your current 350 I bet you will be surprised by the improvement.

 

I would find a car with a bad engine and a clean body and put the engine in there. Why leave a running engine sit in storage when you can have two in cars?
Preferably a Vista Cruiser (I'm not biased), then you can get a trailer and have an ultra-cool 455 powered car hauler rig to drag the Cutlass or anything else around.
I've had my eye on those teardrop shaped retro camper trailers.

The 455 seems like a better choice to me if it weighs about the same and is pretty much bolt in, be more original.
Swapping out that 2:73 gear it should come out of the hole a lot better, a 455 would help a little too.


Allan

 

The 68-69 400 is not one of Oldsmobile's better designs. The tiny bore and long stroke make for shrouded valves and limited airflow. Go with the 455.

 

It's a good suggestion, but what I really want is a BB in my car. I know the 350 is a really great engine, I've put lots of miles on quite a few of them. For kicks, I will try the new gear ratios on the 350 b4 I change to BB.

Glad to hear you're not biased. Not may VCs around here. Only one other problem: I don't have a lot of space so putting another car in the driveway or on the street isn't an option. Maybe later when we move to the lake. BTW, I'm not making a trailer queen, just one awesome car that will be making the car show rounds. Definitely not going to be a daily driver, much as I'd love it to be.

Thanks Joe. I was wondering about that. So it's going to be a 455/400. Looks like the donor car is going to be a 71 442. Let you know when I go to pick it up. BTW, the donor is not running it's in the boneyard. They're going to pull the engine and tranny for easy pickup. Any suggestions about what to look for just to make sure there is no damage? Also should I be checking the block and heads to see if they are original? Not being dumb about this, it's the first time I'm going to do a teardown and rebuild on my own.

 

Ideally it would be nice to take the heads off. But if you can squirt some oil into each spark plug hole, disconnect all the belts and turn the engine by the bolt on the front of the crankshaft you could at least know if it was seized or not. If you had a battery and the engine turned over you could do a compression check on all the cylinders too. Look for coolant stains on the intake by the thermostat housing, excessively burnt (whitish looking) paint on the exhaust manifolds in one place compared to the rest, look for a reall dirty engine down under which may indicate leaking oil (near the back could indicate a leaky rear main seal), since your winters are pretty cold (I am assuming) look to see if any of the freeze plugs have been damaged during storage. Finally, you could drop the oil pan and see what is inside (any metal shavings or such).

 

Got an email from the boneyard about the engine. They don't know how to tell if it's a 455. I never owned one before so I don't know how to answer. I know that the 455 has a wider intake manifold and its traditionally painted Olds blue. (but anyone could paint an engine). Can anyone tell me how to describe a 455 so ANYONE could understand?

And for the TH400 is there a casting number that would clearly label it? I'm pretty sure that if its a 455 it would be hooked up to a TH400, but want to be sure. Eagerly waiting for your replies.

 

Casting number above the water pump - 396021 F or Fa

 

http://oldsjunction.classicoldsmobil...mbers%20Detail

Allan

 

As Joe has said the 396021 F is in the flat spot right next to the oil fill tube. A big letter "F" will be on the passenger side of the block just above the oil filter. It should have letter "G" on the cyl head for a '71. Letter "Ga" if it is a '72. '73 and newer will be letter "J" on the heads. '71 and newer all will be low compression.
Decking the block and milling the heads will help in the compression. A very good engine for todays gas.

Gene

 

Perfect source of information Allan. And it came from our website!! Knew we had stuff, just not where to find it.

I went out to my car to see where the casting is as you described. Right on the money, only mine is a 350 block with the number 2. Guessing the 2 means 1972, that would be the logical comparison to the F, Fa, G, Ga lettering beside the block casting. Is this right?

What would it take to change the engine to higher compression? Or is it worth it?

 

Allen,
If it was mine and I just wanted a little more power and driveablity. I would zero deck the block and mill the heads to maybe 76 or 78 CC's. Without all the info it is hard to say. But it will bring the compresstion up. With iron heads you don't want to go over 10 to 1. If it is just a street car I would run a cam in the 210/220 @.050 range.

Gene

 

The factory did it by using different piston configurations. I see no way to argue with their reasoning.

Same casting/forging is used. The only difference is, how the top is machined. Manufacturing cost is the same for both. More practical, and much less expensive, than casting a separate head or creating two separate blocks for the same application.

Rebuild = new pistons.

As any competent machinist will tell you, your piston choice will determine your compression ratio.

If you were to use your original pistons, you could mill the heads and/or deck the block, but future use of the resulting parts would be limited.

Block and head milling are useful, for specific applications, but should never be used as a "band aid" to cover an unfortunate choice of pistons.

But since I do not work in a machine shop, I probably do not know WTF I am talking about.

Norm

 

Not really. Olds used letters to designate BBO castings (blocks and heads) and numbers on the SBO castings. As with the heads, there is both a casting number and the single letter/number casting designator. The "2' in this case is just the casting designator for the 68-76 350 block. The full casting number will be 395558 2. Don't confuse the casting letter/number on the cylinder heads with the one on the block.

You can get the year of manufacture for a particular block from the VIN derivative stamped on the pad below the no. 1 exhaust port.

As Norm noted, the factory changed the piston dish size to vary CR. All BBO heads (except for the D heads) have as-cast chambers of about 80-84 cc.

 

Depends what fuel you plan to use.

My granny told me about a "kit" that was sold (near the end of one of the oil crises) for the 350 Chev, that used 15:1 compression to gain an increase in fuel mileage on pump gas. Oil prices went down at about the same time, it went on sale to the public, making it an undesirable investment.

But today, !5:1 could not even be used for bragging rights, because no one would believe it.

Norm

 

Noted. Yes it will be a total rebuild (read $$$) including the carb. I dont mind admitting that I not good enough to do all the work myself. I will be getting guidance and help from a friend who is a very competent mechanic - also an Olds fan. May take some time, but I'm going to do it right.

Figured on todays fuel in the 91-93 octane range. Not quite sure whether 87 is a great choice. Correct me if I'm mistaken, but... the 72 Olds owner manual says to use minimum 91 unleaded fuel. Somewhere it seems that I read that todays 87 is the equivalent of the old 91?? Doesn't make sense to me but I'm throwing it out to the forum in case anyone out there has a good lead on this.

Thanks Joe, Norm & Gene for some really good advice.

 

That is correct. The old method Research Octane RO was used, which is higher by 4-5 points. Todays method is RO+MO/2. Todays 94 is equal to yesterdays RO 98.
This has to do with the question Norm... http://en.wikipedia.org/wiki/Octane_rating