Timmy1966_442

Good evening,

I have a guess but I don't want to taint the answers on this one....

My 455 is stamped from what I can read its 30C110961. Casting number is 396021F ("Stick" F).

Thoughts?

allyolds68

1970 455 assembled in South Gate, CA

don71

yea, thats a 455 no doubt. What exactly do you want to know? It won't make much difference, it is what it is.

Timmy1966_442

I was looking through the Tech section, didn't see a "C" code for a plant code. Just curious what the engine is out of.

MDchanic

Interesting that it's red - I'd thought all '70 455s were blue.

- Eric

1969w3155

The "E" heads are from 1970 as well, and the partial vin would have to match up to the vin on the car to be original. The vin will not tell you what it came out of if not original to the car.

oldstata

I think if you have the transmission vin matches you can decode its tag to see what class of car it was might help there if it was swapped as a whole unit

joe_padavano

That's because the Tech section is A-body centric. Only full size cars were built at South Gate during the 1970 model year. West coast A-bodies were built in Fremont, CA.

allyolds68

I found it by searching "assembly plant letters" on ClassicOlds, found this:

https://classicoldsmobile.com/forums...engine-id.html

and then realized that this list:

wasn't quite right because there's no such place as "Southdate, CA".

So I googled GM plants in CA and came up with "South Gate". BTW, South Gate was a BOP plant run by Pontiac

Timmy1966_442

Is there a way to tell if this motor was a low compression or high compression with pulling the heads off?













Also, Thank you all for the info. Nice to have a group with so much collective knowledge.

oldstata

70 should be a higher compression before the smog motors hit hard if it's original my 69 marine motor was rebuilt with lower compression guts but looking at the piston with the head of would tell you

MDchanic

A '70 455 could be either 9:1, 10.25:1, or 10.5:1.

The 9:1 pistons had a half-moon notch at the front-facing side.
The 10.25:1 pistons had a V-shaped notch.
The 10.5:1 pistons were flat tops, with no dish.

You can look in through a spark plug hole with a bore scope to see them.

- Eric

svnt442

That was a copy and paste on my part and I never bothered to check for typos.....fixed.

svnt442

I thought only the W31 got a 10.5:1 piston. I only remember seeing 2 pistons listed on the service manual for the 455 and 3 for the 350.

MDchanic

Maybe there wasn't a flat top in 1970. I thought there was.

- Eric

Timmy1966_442

Old post but I thought I'd update. I bought a $16 lighted Borescope camera ebay and identified the pistons on my 455. It is 9:1 compression. Not sure what that changes but now I know. Cool tool if anyone else is curious or needs to inspect cylinder walls or pistons.

Now should I be picking a different cam with the lower compression to keep it semi matched?

Octania

link to that borescope for us CB's?

Timmy1966_442

You bet....

http://www.ebay.com/itm/151114740957...84.m1439.l2649

It was almost $19, not $16. Less than 20% over/under statement, so technically not a lie

2blu442

That is a cool looking gizmo! So does it actually record the photo, then you download with the USB port? Or do you have to attach it to a digital camera?


John

MDchanic

Neat toy. I could really use something like that from time to time, and I've been reluctant to spend $200 on something that will be obsolete in 5 minutes. $20, on the other hand...

- Eric

Timmy1966_442

Plugs into your computer like a USB. Software allows you to view, capture video, and take pictures. It was very easy to use. Here are a couple of the pics I took with it...

Timmy1966_442

I almost bought the one at Harbor Freight before I found this. One of those things that ends up in a drawer. But its cool to have about once a year.

oldstata

How big is the pic on the computer ? Is it the screen size or a tiny box

Timmy1966_442

Picture is about 1/4 the size of your screen. But I haven't played around with the settings much.