junkmanjr

Ok guys Im new to this forum and before you possibly murder me for my possibly stupid question hear me out. I had a great passion for early Oldsmobile V8s before I joined this forum Im well educated on the Kettering 1949-64 V8s 303 324 371 394s but Im a little green on later Olds V8s and their differences. Know plenty about Chevy SBC BBC but thats kinda pointless here. Anyway basically from what I gather from SBO vs BBO is the valve covers are the same but intakes are not interchangeable due to the BB higher deck height so it requires a fatter intake to compensate. Im working on a 72 Cutlass with a 350 so small block stuff is what Im after. Anyway Im getting to my question be patient......I picked up a Edelbrock OL4B which is small block I know but it has been modified pretty heavy by a ex racer the ports have been raised making them straighter flow and taking out some of the curve of the runners but in doing so its had some serious welding and machining. They did an awesome job I would hate to imagine what it would cost to do all that work and hard to tell unless your looking for it. So due to the mods on it its not exactly the perfect example to compare anything else to measurement wise or looking for exacts Im sure it seats fine and everything but comparing it to another intake for verification might be tough. Anyway Im cruising craigslist and come up on a Offy intake that a guy says is for 400 455 for what I bought it for I couldnt pass it up figured worse case scenario I would sell it and make a buck or trade it for something I need or want. Anyway I get the Offenhauser intake home and compare it to the Edelbrock intake just to be sure its not a small block and I be damned I think it is but want to verify with someone more knowledgeable than me. Like I said tough to compare it straight up to the Edelbrock due to the mods on it. And the Offy seems to be pretty early its a 360 degree dual port but it says "patent pending" above the dual port print and I looked for a part number on the bottom like 99% of Offy intakes but a blank pad no number. So I dont have a part number to cross reference and I've looked over Google images and cant find another like it. Anyway the Offy intake is it small block or big block Olds? And if you got this far thru the post without cussing me or saying dumbass heres a couple of bonus questions if the Offy is small block which would you run on a stock motor the Edelbrock or the Offy? Heres the pics. Sorry if I'm an idiot to some. Thanks for the replies and info in advance guys.

Side note if the Offy is a big block Im open to trading on a aftermarket small block intake and also if someone has a hard on for the Edelbrock OL4B I would trade it also. Have a nice day thanks.

nsnarsk65cutlass

It's hard to tell from the pictures,but the offy intake appears to be the same width as the ol4b low deck aka small block intake.

junkmanjr

Thanks for the the reply thats what I was thinking everyone is whos read is probably thinking why the hell dont you just try and bolt it down to the motor well thats a problem cause the cars about 4 hours away right now.............oops kinda forgot to mention that in the first post

VI Cutty

BBO intake measures about 14" across at the top back end while the SBO is about 12"...so width should help you determine application.

Looks like one is single plane while the other is dual...about all I know about that is an awareness that the different setups perform differently and I believe the intended driving/power results would determine which is the better option.

There, I'm done!

MDchanic

See Here: https://classicoldsmobile.com/forums...-pictures.html



- Eric

joe_padavano

As noted, an SBO intake is about 12.5" wide. A BBO is about 14" wide. The Offy is a gimmick design. Being aluminum it doesn't even make a good doorstop. There's a reason why no other intake manufacturer in history has used this design. I would certainly use the OL4B over the Offy.

The only issue is the port work done on the OL4B. I'm having trouble following your description, and the photos aren't terribly helpful. Are you saying that the ports where the manifold mates to the head have been opened up? If so, this was likely done to match the larger BBO ports when using BBO heads on an SBO. The flow mismatch if bolted to stock SBO heads will likely negate any HP gain (or worse).

FYI, if this is the case, I'd be interested in trading you for an untouched OL4B. I plan to run BBO heads on the 403 going in my 64 Vista.

olds 307 and 403

The OLB4 is another dated design. Mark did a dyno test with the BBO version I believe, didn't do very well at all. Are the ports welded at the top and opened up bigger? I think only the RPM and Victor SBO intakes have enough material at the top to cover the BBO ports.

D. Yaros

Will somebody please help eradicate my ignorance.

What in the heck do SBO and BBO mean? Is it Short Block O_____ and Big Block O_____?

Thanks!

joe_padavano

Hint:

SBC = Small Block Chevy, BBF = Big Block Ford, and the name of this forum is ClassicOldsmobile.com.

Do the math.

oldolds88

looks like all the runners were welded on. maybe added on to the small block runners straighten and lengthen them, to fit the big block?

Fun71

It didn't look like there was an additional 2" welded on to me.

junkmanjr

Well I think I got my answer the thread was kinda started to id whether the offy was for a small block or not, got that answered. Best I can tell on the OL4B is they raised the ports for racing I assume the ports are about about 2.5 inches tall and 1.5 wide. They altered the flow of the runners I guess to take some of the curvature out of the runners and make the gas flow more staight to the heads. When they altered the flow pattern they had to cut some stuff off the top and replaced it accordingly to achieve what they were trying to do. I wouldve hated to pay the bill on that work