Corvette Forum : DigitalCorvettes.com Corvette Forums banner
1 - 4 of 4 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter · #1 ·
Guys, I've been trying to find some definitive comments on swapping a BBC into a SBC car. I know that a 454 was an option in 1973, so I don't see this being that big of a chore.

What all has to be changed? Radiator? Do front springs need to be changed if I go with aluminum heads/aluminum intake? Any way the BB will fit under the hood? None of these things will be a problem because I can be assembling the new engine and procuring car parts with no down-time on the car.

I'm on the fence right now trying to decide whether to build a 406SBC or a 468-496BBC. I like the idea of just pulling the 350 out and putting the 406 in, but the sound/looks/power, etc. of the BB is so appealing. I've assembled a SBF, a Ford FE, and a SBC....I'd like to do a BBC....so that's another pro for me.

Anyway, all comments are welcome....I need some help as I'm just plain stuck right now.
 

·
Registered
Joined
·
306 Posts
I went the 406 route for several of the reasons that you already outlined. i, too, was thinking about the appeal of the big block, but have never had one so I shouldn't notice the difference (I hope). My 406 was desktop dynoed at just under 400 HP and 450 pounds of torque. Should do. Having said this, it only maters how it performs in the car and you can never replace cubes. The more you have, the better.
 

·
Registered
Joined
·
4,075 Posts
http://www.digitalcorvettes.com/forums/showthread.php?t=81404&highlight=big+block

The link above is on big-block swaps into later C3's. Springs, exhaust, radiator are the obvious extras. You'll also need a bigger carb. My motor had no fuel pump boss, so that adds a fuel pump, regulator, filter, and lines. Put in a fuel cell at the same time as the gas tank had a rubber liner and I decided not to mess with welding on a sump. My motor had no ball stud boss for the clutch z bar, so had to fabricate my own. I put in a lakewood bellhousing and big driveshaft when I did the motor.

It sounds like what ever you do is going to result in more HP. You should probably consider going through the rest of the drivetrain. I've broken two rear ends and it looks like I'll eventually get rid of the IRS (I'm tired of spending money right now). I may just drive carefully for a while. I also broke one of the twenty-plus year old rear axles, they are both replaced now.

The extra horsepower causes the chassis to flex, so added a roll cage.....
 

·
Registered
Joined
·
421 Posts
Big Blocking my SA was the best thing I ever did for it, followed by switching the auto trans to a stick, and was the easier of the two conversions.

IMHO, the 496 (that's where I'm going next) gives excellent bang for the buck, especially if you've got an old Mark IV block that will clean up at 0.060" over lying around. Lots of aftermarket support for that variation, too. The weight difference really isn't all that much w/alum. heads, given the order of magnitude increase in available torque. The only downside is that rats ain't exactly cheap to build up.

Depending on your current spring rate, going to stiffer coils may well be in order. There's a few brackets you'll need, but you may be interested to know the same mounts fit both the SB and BB. C3's were just as much made for rats as they were mice. :cheers:
 
1 - 4 of 4 Posts
Top