Brooklynlh

I have a 1968 442 with a 455 in it. I think it’s numbers matching. What’s the biggest cam I can run in it without a stall?

no1oldsfan

Obviously not numbers matching. To Your car anyway. 68 442 came with a 400 not a 455.

Brooklynlh

sorry about that. I don’t know. I was just going off the numbers on the block. I know it’s a 455 motor an I want to change the cam.

Brooklynlh

RetroRanger

No1 is correct the 68s and 69s 442s ( not including HOs) came w a 400ci engine 70-72 could be had w a 455.

is your 455 engine stock or rebuilt?

Brooklynlh

as far as I know it’s stock.

joe_padavano

Just out of curiosity, what "numbers" were you going off of that were "matching"? There is a VIN derivative stamp on all 1968-up Oldsmobile blocks. This should MATCH the VIN of the car it was originally installed in (hence the term "numbers matching"). As noted, no 442 came from the factory with a 455 in the 1968 model year. The VIN derivative will tell you the exact year of the block - the second character of the VIN derivative will be the model year.

Brooklynlh

Brooklynlh

U can tell me. I know a lil about cars but not to much about old schools. I’m 41 years old lol. This is my first time getting an old school an trying to get the motor right b4 I stick it back in

joe_padavano

OK, so what's the casting number on the block, above the water pump?

Brooklynlh

joe_padavano

That casting number is a 1968-69 400 block, not a 455. Congrats, you do have a correct, numbers-matching motor, but it's not a 455.

Brooklynlh

thanks. I’m glad I know now. So what do you suggest me do? I want to beef it up some. Not racing or anything just cruising but when I hit the gas I want ppl to know it will go. Lol

Vintage Chief

There is nothing wrong w/ a 400 engine. In and of itself, if you're going to COMPARE the engine to later engines the 400 will fall short, but there are some modifications you can perform e.g. headers, rear end, cam, etc. The first place to begin is tuning the vehicle accurately and precisely. There most likely won't be one single item, but you need to be aware of cost and time involved. You plan on driving it this summer? Here's a good read on the 400. You own the 1968 Oldsmobile Chassis Service Manual (CSM), correct? If not, buy one ASAP. Lot's of threads/posts/discussion regarding the 400 - consider performing several searches to determine which way you think might suit your budget & planning.

400 Engine

Brooklynlh

Yes I was trying to get it ready for this summer. The motor I have runs fine. I just want to beef it up. I will look into getting a 400 CSM tho.

Vintage Chief

Post #1 you stated:

Post #9 you stated:

I'm sorry, but you can't have it both ways.

It's either in it or it is not in it. We tend to pay attention to these small details since they can contribute to work effort, timeline, parts availability, etc. Others can make more informed decisions to help assist you in determining what is feasible within a certain time frame.

BackInTheGame

Buy an original CSM, not one of the reprints. And the quickest way to more UMPH in time for summer is headers.

droldsmorland

As you may know, simply stabbing a cam into an Olds engine (any engine) is asking for trouble without considering the whole combination. Cam must match the rest of the setup...The valvetrain geometry is very important on these engines. Get it wrong it will ruin your day. The combo must take into account your intended driving habits, converter stall, rear gearing, carburation, intake profile, exhaust type & size, and ignition.

Do you want to upgrade the rocker assembly? Are you shaving the heads and block? If yes you will need custom length pushrods and a port matched intake.

Give BTR a call or email or purchase Bills book. http://btrperformance.com/ Call the cam suppliers tech line and ask questions. Building an Olds is far from building a Chevy.

The G block 400 is a low-end low rpm torque engine. It does its best work between 2500 to 4500-5000 rpms. Any higher you'll be sweeping up rods without significant top & bottom-end beef. At that point, you are farther ahead switching to a beefed/stroked 455, put the 400 on a self.

So there isn't one simple answer how big of a cam can I stuff in there. A W30 profile may be what you want with a slightly higher than stock converter, 2500ish. Need to watch the push rod length and check for spring bind. Now the carb, ignition tune and rear gear need to match this setup.