Hello, I am pretty new here, and I have a couple of questions.
I have a 76' L48/Auto with A/C, but I am considering going to a 454/auto.
1. Has anyone performed this swap, and how tight is the engine/AC clearance?
2. Does the Vette require a special oil pan for BB's?
The engine probably will not come from a Vette.
3. Were there any changes from 74'to76' that would prevent this from being a fairly straight forward swap?
4. Do the SBC and BBC engines share the same bellhousing bolt pattern?

These questions may seem simple, but this is my first Vette, and though I have toyed with plenty of other SBC cars, Monza's/Malibu's/Camaro's, I have never owned a BBC.

I would be greatful for any info....
Thanks

|UPDATED|11/1/2002 4:58:52 PM|/UPDATED|

My next door neighbor has a '75 that he replaced the stock L48(82?) motor in with a 502/502 GM Crate motor when the car was new(orig owner). I'll be talking to him sometime later today(about my 75) and can ask him what problems he had. Hope that I can get something helpful for you!

Scot

That would be great, thanks.

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Welcome,

The swap will be realtively easy. The two major stumbling blocks will be the hood clearance and the accessory brackets. The big block 73-74 cars had an intake that was near flat and the intake runners actually went down then up to the head intake ports. Poor performance at best. All this to maintain the same hood from small to big block. You can get aftermarket hoods with the L-88 hi-rise. This will allow you to use a Performer style intake.

The brackets are another beast to tame entirely. You will have to experiment with several set ups at the very least. There are some pre-packaged kits but they run in the neighborhood of $800.00. I am going through this with a 67 Impala that I have dropped a big block in.

Alex

Any particular reason you want a big block? You will probably have a much easier time of it if you use one of the HO 350s that are available as a crate engine, pan to carb for about 4 grand. The 350s are pushing more fly wheel HP than the big blocks created stock as gross HP and you can get them with fuel injection for better reliability.
Just a thought.

Alex, I had planned on going with the L-88 hood regardless of what motor I used. My major concerns were the oil pan, and trans compatability. I would look to use as many factory BB parts as I could get my hands on, but i am trying to get an idea as to what I am goimg to have to spend on this.
Glenn, I have toyed with plenty of SBC's, and yes they run great, and you can ring alot of hp out of them for very little money, but I am ready to try a BBC. Since this car won't be running flat-out for long distances, I am more interested in making large amounts of torque. If I do end up using a SBC, I will start with the original block, and build from there. I had considered a TPI 350, but I would really prefer to go with Big Block.

Here's a "Big Block Information" link:
http://www.roadsters.com/bbc/

Has some good info on all the subtle differences between the various big blocks out there.

Hope it helps!

~ Joe

Any info is helpful Joe, as I know next to nothing about BBC's.
Thanks for the link.

the oil pan and trans will be no prob. as long as the oil pan is not out of a truck. the oil pan on cars are the same. i have put big blocks in a lot of cars that didn't come with them. if i weren't trying to stay original on my vette i would do it.even the motor mount on small block and big block are the same.