rustycragars

Hi, new here. Got an Olds 350 recently to replace the overheated and underpowered 260 that came in my '81 Cutlass. Not sure if it's a 350 Rocket or what, and after researching I'm finding that "Rocket" may not be anything special? Going into this motor I thought a 350 Rocket was a high compression Oldsmobile motor...? Anyways, any info on this motor or links appreciated.

Searching around the internet it seems to be hard to find info on an Olds 350...I think I'm almost positive that this is a '73 or '74 motor (395558 on the front top of the block to the right of oil filler tube) with 7a heads. Any other numbers I could look into on this thing?

The motor didn't come with a carb so I got an Edelbrock 600cfm Performer Series to go on it. Right now it's got the factory manifold so I'm not sure what'll be different with that...it looks like the throttle linkage might need some modification of some sort. Would it be recommended to get an Edelbrock manifold?

I've ordered a '74 factory service manual for this but it won't arrive til probably next week. I've pulled the pan and manifold and am considering pulling the heads. But I'd like to get the motor all sealed back up at least by this weekend and I'm looking for torque specs on everything motor related, does that exist somewhere on this site?

Last question (for now), can I pull the heads but keep the valves and springs and stuff in place to replace the head gaskets? Or will that mess up the valves, springs, etc? I'm not very familiar with motors when it comes to what's under the valve covers and the intake manifold

Here's some pics of my project for your thread viewing enjoyment:

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captjim

Unless the heads have been changed, that is a 71 350 engine, 8.5 to 1 compression ratio, good candidate for a street engine. Why are you going to pull the heads? You will actually lose some compression as they used shim gaskets and the replacement gaskets will be thicker. Yes, you can remove the heads and not affect the valves or springs, just make sure that when you install the rockers you do so on the low part on the cam lobe.

If you can afford it and have the time, with the intake off it is a good time to upgrade the camshaft/lifters and replace the timing chain and gears. A mild .450/205 cam would be a significant upgrade over the very mild (.400/195) stock cam. Keep the factory intake and get a good Quadrajet, it is the best all-round carb for a daily driver.

rustycragars

Not sure if the heads have been changed. I can't find the site now where it listed the casting numbers and corresponding years but I thought for sure it was a '73 or '74. But now I googled Oldsmobile 350 395558 and came up with what seems to be it could be anywhere from 68-76? Confusing...could you please ease my mind as to it being for sure a '71? I'm not sure if it even matters in the long run anyways, but I did order a '74 service manual so I'm hoping that provide the necessary info even if not the exact year. Thanks!

captjim

You probably went to the "olds FAQ" section of 442.com. There are countless inaccurate statements there. Classicolds has attempted to rectify the situation here,
https://classicoldsmobile.com/forums/wiki-site/

In any event, all blocks from 68-76 are the same. There are different combustion chamber sizes and piston dishes which yield different compression ratios. But other than that, there really aren't that many differences. 73-76 350s have #8 heads which have a very large combustion chamber and not-so-great exhaust ports. On a stock 7a headed 71 350, the Cr should be 8.5 to 1, +/-. The 71 has hardened seats and flows as good as any 350 Olds engine. As I stated, IMO, it is a good start for a fun little street driver.

svnt442

Jim....7A heads are 72.
Check the block below the #1 spark plug for a machined pad with some numbers stamped into it. It should read something like 32MXXXXXX. It will be behind the alternator bracket on the side of the block.
Get a pick of it for us.

captjim

Yep, you are right. 68-69 are #5, 70 are #6, 71 are #7 and 72 are #7a. I always do that.

70 cutlass s

The carb you have is fine. I had a 600 performer on a 350. Drove the car for seven years never had a problem. I used a performer intake with it. I don't like adapter plates. They have a greater chance of leaking.