how to put a big block in a small block c3
 

I am sure this has been done 100s of times, are any c3 years easier, can anyone point me to an article describing in detail how to do this.
Thanks in advance.
Joe

Never put a BB in a SB car, and frankly never would. A small block can be built pretty strong, and BB's are 100 lbs heavier. The real ticket if going through all that trouble, is LS. These are 200 lbs lighter than a BB still, and can have fuel milage like an econo car, if geared properly. I've had a couple newer LS cars, and highway milage approached 30 mpg. Currently have an LS7 car, and gets 25-26 mpg highway. This thing really rips snot too. Think an LS3 is probably a better choice, and what I'd do.

totally disagree with above post, it's his car , it's been done 100's of times, no reason he can't do it. he wants a BBC old school motor , nothing wrong with that ...it's his car. Let him play. Maybe it's his dream.......not yours...

Do a search . Bound to be dozens of conversions.

It's more trouble doing all the little stuff, lots of small parts to find , make , but the engines will fit fine.

if it floats your boat do it...it's Your car .:rock:

Off the top of my head.....

1) Radiator
2) Front Suspension
3) Acc. mounting brackets
4) Bigger gas tank :D

Very do-able.....and you will LOVE the big block power....nothing like it :thumbs:

I don't think it all that difficult....I'm considering it myself....or a 383 stroker....not sure yet...:rock:

Search the hot rod magazine archives. This swap has been going on since the time the big block first appeared. Be aware there is more involved with this swap than just the engine. You will also need to make suspension and cooling system changes.

Big blocks were optional for the 68-74 Corvettes, so pretty much everything you will need for the swap is available.

:thumbs:

I have already done it and on a bologna budget.

Changed front springs to bigblock springs. Could have used the original radiator, but it was in sad shape, changed to a 3 core aluminum. Also installed an Electric fan from a taurus. Motor was from a 85 mobile home. got it from carb to oil pan, with only 72,000 miles on it. had to change the flywheel on it to match my th350 bolt pattern. Fabbed up the steering arm and lowered the ram so it wouldnt hit the deep oil pan. Finally got the pulleys squared away and used old school mid sixties brackets, heck of alot cheaper than getting the other setup. All in all everything including the motor cost about $1,200. I am very happy. Now since the motor is stock, I am fine using the th350,and original small block halfshafts and ujoints. If I decide to go farther with the engine, I will change everything accordingly.

Did this a while ago on a '69 (previous car). Left the radiator and gas tank alone, but would advise a better radiator. Also need lots of other parts like springs, motor mounts, rear u-joints (for originality and safety due to more HP/torque), also manifolds and exhaust are different, off the top of my head.

Best thing I ever did to the car besides a/c delete and hydroboost brakes.

Been done many times, my 72 included. Here are some good linke:

http://forums.corvetteforum.com/c3-t...r-rebuild.html

http://forums.corvetteforum.com/c3-t...going-big.html

I put a 540 in my 76 vette. You will need a larger radiator, alternator, power steering brackets and pulleys. I used my SB front springs and it lowered it about 1 inch. Headers. It´s not real hard to do. I bought all the stuff for a 74 big block. I would do it to my 80 if I had a BB. Nothing like opening the hood and seeing all motor. Sure you can get a SB to run as good. But nothing like the sound of a BB and the look of it.

bb parts
 

let me know what you need i have a set of bb hooker super comp ceramic coated headers (under car) also a complete set of factory pulleys (alt, ac. ps) and a used aluminum water pump. all parts are used but in great condition

Unbolt small block, pull it out. Drop in complete (brackets, accessories, exhaust, etc) big block. Then you may want to beef up the suspension for the added weight, and consider cooling needs/improvement.

Basically a bolt in operation using off the shelf parts.

It doesn't really matter what year C3 you have, the conversion is pretty much the same. BB'ed my '78 SAE ages ago, and still feel it's the best major mod I've ever made to any vehicle, other than putting playing cards in the spokes of my Stingray bicycle. The downside is, once I crossed over to the dark side I've never been satisfied just leaving things alone since...

If you have the budget - and with a high-perf BBC you'll need one - definitely go for aluminum heads, intake and water pump to minimize the weight increase (an iron BBC so equiped only weighs ~75# more than an L82 SBC). And, before anyone tries to convince you that you're about to ruin your car's handling, bear in mind those additional pounds sit behind (not above) the front axle, and can be readily offset with some astute chassis tuning.

In any event, before you pull the trigger I'd make sure local regs won't make your hard work an act of futility. Or, you could just move to a more gearhead friendly location. My $.02

:cheers:

Basically a simple switch in a C3.

1. Remove small block.

2. Remove small block exhaust.

3. Install Corvette oil pan on big block. Otherwise, you have to jury rig the steering like the guy above.

4. Be sure the big block as the short water pump and pulleys. These have not been on any passenger car big block since 1968.

5. Have all the right big block brackets as mentioned in other posts.

6. Drop the big block in.

7. Install big block exhaust.

8. Put all the big block brackets in place.

9. Use the right radiator hoses for a big block. Ask for hoses for 1974 for any year after that.

10. Depending on the year, you may need a different radiator.

11. Install the big block front springs if you sink too low. Most rubber bumper cars could use a little drop in the front end.

piece of cake.....

tools required:

*Large shoe horn

*Large tube of KY jelly

LOL...seriously though, not a major undertaking, no real difference in the engine bay/frame/motor mount area between BB and SB cars....heater box might be one exception off the top of my head.

:iagree: some caution-

you need some amount of mechanical skill this is not a beginner level project. It was done from factory so its not a 10/10 or anything but its not for the novice.

BBC is a torque monster even in stock trim, stuff in driveline could / will break unless upgraded.:thumbs: that's why I love them

I would make a list of what you have, what you need and then look at the cost. The 1200 above is a sweet deal. My guess is that you should figure it out for your scenario and then add 50%. (50% is a good thumb rule for Vette project budget over runs)

good luck:cheers::cheers:

I put in BB with A/C springs. I reused the motor mounts, radiator, radiator hoses, fan, flywheel from the small block. I used the water pump and alt. bracket from a 68 Chevelle. My radiator cools fine, but I live in Ohio, not Texas or Arizona. The Route I took may not be for everyone, but it worked for me.

I just swaped my small block for a big block no problems at all, bolts right up same motor mounts new big block pulleys and brackets, well worth it to me to do the swap it pulls like a freight train, go for it, you wont be sorry Attachment 48143163

Do you have to swap transmissions with a big block?

I love how everyone complains how the BB is a whole 100 lbs heavier. So you are telling me that when you SB owners have a passenger in your car that your performance goes to crap? I doubt it.

That being said, I have a 72 BB. (454) I can tell you that while being a torque monster, my moderately worked 350 felt just as strong. SB's are MUCH cheaper to build and maintain as well. Unless you are willing to drop a few grand into a BB (yes, they EASILY make 600 hp, but thats going to require heads -2 grand- and pistons -800 bucks)....for about 1500 you can make a small block make 400HP.

My own .02 is stay away from the BB. They are more myth than reality.