Hi all! I am wondering what items must be changed in a '73 small block to big block conversion? I am very happy with my mild small block but i have been given a near new '91+ 4 bolt big block and at first i said "Na, the sweet (little) 350 is great....but somewhere back in the grey matter a small neuron said"mmmmmm 454!" Anybody know just whats involved apart from obvious,
Car is not numbers match.
all the best
Geoff

Geoff, I don't think you should go to all that trouble. And since my car is an "ex" B.B. I would make the supreme sacrifice of getting rid of it for you!

There's a pretty fair amount of work in properly swapping a big block into a car set up as a small block...new radiator, front springs, exhaust, hood since a small block hood doesn't have the clearance, further suspension changes front and rear...that's a short list. Not that it can't be done and done well...just a lot more to it than it first appears.

It's your car and your money, but if you're happy with the way it's running with a small block, I'd stick with it. It you get that good a deal on the big block, I'd either re-sell it or maybe store it and look for a car that was an original big block with a small block in it now (no shortage of them) or no motor at all.

I also had visions of a sb to bb conversion. It didn't take much clear thinking to decide against it.

couldnt agree more..

even if you make this BB swap.. the brackets, suspension, radiator, etc will nickel and dime you to death..

sell the BB and use the money to "enhance" your SB..

a BB does have the coolness factor....

but a tricked out SB can actually be a better street or street/strip engine.. safer at higher rpms. can get decent mileage when you want it. parts are much cheaper.

a BB will always suck gas.. also the weight distrbution is much better in a sb.

a BB can be really cool.. its just usually more trouble than its worth.. (this from the guy who replaced a blown up 231 v-6 with a BB in a 80 pontiac grand lemans)

I'm also considering a BB in my 79. I need to replace the radiator, exhaust and disconnect the non-functional A/C. So, I'm thinking crate BB or SB. Is it just a romatic notion to have a BB in a Corvette? Coolness factor? Or will a tricked out SB with 450 ponies/450 tq win the day. The problem I'm having with the decision is I have really no way to compare the two engine choices. I suppose there are two schools of thought. One being, there is no replacement for displacement so the BB wins. Good HP, great tq from the get go. On the otherhand, a tricked out SB has it's advantages. Overall it's a more cost effective solution up to a point, 500 horses, then it's pretty even. So where am I going with this? Who knows? Anyway, thanks for listening to a fool and his money (or lack thereof). Opinions?

Do'nt forget "a fool and his money are soon parted" a good small block can be a thing of beauty when its pumped up and chromed up nicely

I once had a diehard collector tell me that if you want an investment or a show car buy a big block, if you want to drive it, buy a small block. I don't know if I personally agree with him or not but I do know that the weight distribution with a small block is nearly and ideal 50/50.

What about a 383 stroker? They've become very popular and there are a number of proven build kits out there. You get the benefits of the increased cubic inch displacement without the weight of the bigger block.

One often overlooked option is a SB 400 CID. These can be very impressive. The extra 50 cubic inches can make a difference. Granted the 383 stroker has some great torque, and is a very good option.

kstyer said: One often overlooked option is a SB 400 CID. These can be very impressive. The extra 50 cubic inches can make a difference. Granted the 383 stroker has some great torque, and is a very good option.

I agree a 400 is a powerful engine.. but ive always had heat problems running them anything but bone stock..