Ok, decided to get a short block and switch my gear over to a big block. i am already running Edelbrock cylinder heads. They fit the BB. Can anyone think of anything that will not switch over to the new motor? Will the mounts line up? I am under the impression the external dimensions are the same. Am I wrong? I don't have air, just PS and an alternator. How about those brackets? Will the crossmember have to be moved? Should I use the search engine on this site? Have aliens landed in my yard? Just asking.

 

i think the headers are diffrent for the bbo since the taller deck height . i dont know about the brackets . I also think the mounts for bbo and sbo are the same.

 

I was going to do the same thing last year. Bought a 455 and it turned out to have a badly cracked block. But, the engine mounts are the same. I was going to buy new ones just because of the torque the motor puts on them though. The brackets for the alt and PS should be able to transfer straight across, but I think you'll need different belts as the 455 is a wider block IIRC. You shouldn't have to move the crossmember if you are just bolting 455 in place of a 350.
Crap! Aliens have indeed landed in your back yard.....

 

I'm thinking that if I am already using BB headers with the Edelbrock heads they may fit. My fingers are crossed.

 

Oh yeah they should then i was under the impression you where using sbo headers.

 

I did the swap years ago, and wasn't a very big deal. As mentioned, because of the longer stroke, the 455's a bit taller and wider. I did have to modify a couple pulley brackets, with some modest cutting/welding, and the belts are longer. Pretty sure 350 and 455 heads have different intake port heights. They'll physically bolt on, but don't think the ports align up perfectly. Not 100% sure of this though. The 442.com site does or did have a pretty good Marlan Davis article on the different Olds engines. If you can't find it, PM me an e-mail. Mark

 

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Ignoring any problems with clearance to the E-brock heads, any 1968-76 accessory brackets are designed to fit both big and small block Olds motors. No cutting or welding is required. Be sure to use the water pump that matches your brackets and pulleys. The SBO oil pan fits a BBO, but you should use a correct BBO pan. Pickups are the same. Of course the intake will be different due to the wider block. Distributor is the same.

 

I foresee a huge clearance issue in your future.....

Your 68' won't fit in the traffic lanes properly, if you are driving SIDEWAYS everywhere you go.

 

Joe, I'm using a Moroso 7 quart unit just to help the Saudis. It should fit as well. Do you think the water pump I am using on the small block will work on the BB? That would clear up a lot of issues regarding the swap.
Jer, You rode in the car with the small block and it was and still is a lot of fun. I just need more power!!! Everyone can understand that!
I think I'm going to a set of 3.23s when the car is down. It has 3.73s now and seems a bit much.
The car is complete with a 780 Holley, MSD distributor and box, beautiful exhaust system, great suspension components, it just seemed so damn slow. And I'm NOT putting in an LSX motor. No friggin way. It's not for me.

 

Before putting a bunch of cash into a rear gear change, you may consider changing to a 700R4 od tranny. What I did on my car with 3.73's, and like running a 2.56 axle on the highway in 0.70 od 4th. Probably better, because of the converter lock up. Also, with the 3.05 1st, like running a 4.55 axle there too. Guess, you can why this is such a popular swap.

 

Yes, you must use the pump, accessory brackets, and pulleys as a matched set to avoid belt alignment issues. Also, remember to reinstall the two spacers between the PS pump bracket and the block.

 

Delta, the car was switched to a 4 speed from an automatic so an automatic overdrive is out of the question. I like my hot rods to have a clutch. Just sayin.
Joe, thanks for the advice i will follow.
Joesw31, I am running BBheaders on it now with the Edelbrock heads I put on a couple of seasons ago. The 3.73s are a tad too steep to drive on the highway which I wouldn't mind doing once in a while. The attraction of a rockcrusher 3.73 combo thrashing down the road is very enticing. I think I'll leave the gears for now, see how I like it and if I don't, change them. Thank you guys for your advice. I thought it would be easy and it always starts out that way. Then...........................well, you know what happens.

 

Turns out every post on this changeover was correct. The headers didn't work. Everything else did. This is a great site for information like this. Thanks again. I having the car chassis dynoed before it's put away for the winter. I'll post the dyno sheet when I do.