Car currently has a tired non-original 327 and 4spd in it... trying to make the decision on whether to build a stroked SBC or commit to a BBC build. Obviously there's no replacement for displacement, but I'm not looking to spend $20k either. I read some posts here but none of them really answered my questions - it seems like other than a larger radiator, mounts, and the water pump it is pretty much a bolt-in swap? I'm also putting a Borgeson box in over the winter so have you BBC owners had issues with clearance?

If anybody here has a stroked SBC, are you satisfied? Is there enough juice in the go-pedal for you?

I'm also considering the 5spd swap plus 3.73 rear gears to liven things up a bit... just looking for opinions here to help me decide.

 

Negative. Everything from the radiator core support back to the bell housing will need to be period correct (assuming period correct) BBC parts including the hood. Cost for all that will be around $10-15K to swap from a SBC to a BBC.

 

It really depends on how much horsepower you want. (Speed costs money, how fast do you want to go?). I have a 440 SBC stroker because my car was originally a small block, so it would fit right in with no other changes needed. Satisfied? Yes. But at times I wish it was a BBC because of the potential of more horsepower. Can't get 900 streetable HP from a small block. But it's fairly quick with my almost 700 HP. I also have the Borgeson, but no clearance issues with the small block.

 

That's just it - I've had the car for 3 weeks and the tired 327 is bumming me out. I don't need 700+hp necessarily, I want good low-speed grunt that doesn't fall flat once it hits 4500 RPM. I have a period-correct 427 block that I had planned to build into a blown street motor for a 68 Impala I'm building, but I figured maybe build that for the Vette and do a blown LS motor for the Imp. I don't want to get into a huge ordeal with the Vette so I'm leaning towards a nicely built SBC stroker, but if everyone here says the BBC is the way to go I might do that instead.

 

I built a 327 for over 400 hp with 4:11 and a 5 speed. Loved it right up until the roller lifter broke.
I swapped in a 396 then a 427. Both had bearing issues but thats another story. I dont run borgeson, there is no need if you set up the saginaw correctly. For either one you need a big *** radiator andcelectric fans so you dont need big fan shrouds. You need a L88 hood for both and you can run a modern serpentine belt so you can avoid all the stock belts if you want to.....the big block will cost about twice what a 450hp sbc crate motor will cost...500 hp sbc may be closer to 8k when done. Big blocks are the same no matter if its 300, 400, 500, or 600 hp.
You are going to wantva spreader bar and you need stiffer front springs for the big block

 

Doesn't sound like you're too worried about originality...so things get a LOT easier.

First...big block bolts in with no issues. Mounts, bellhousing and even clutch will work if it's strong enough. If it's a 396/427 the flywheel will work too. 454 needs a different flywheel if it's still externally balanced. Unless you're going road racing, the stock small block springs are likely fine. They will compress a little which will give it a little rake which looks good. If you want stronger...springs are cheap. Radiator can go several ways. My car has a stock BB radiator and shroud along with a engine driven steel flex fan using stock size pulleys. Runs cool...and it makes over 1200 RWHP. They make larger aluminum radiators that fit in small block mounts if needed. Exhaust is just a set of headers and the Borgeson is no issue with clearance. You'll have to come up with brackets depending on accessories. My PS pump mounts using Borgeson brackets and the alternator drives off the PS pump ala C3. I used the cast iron alt bracket like all Chevy's used back then on the bottom and a chrome universal one for the top.

Cost of the engines depends on what you do them of course. I always say if for whatever reason you need to buy a crank and/or pistons on a 454....no reason to not make it a 496. Same price. 454's to build are relatively cheap out there these days. Iron oval port heads can make near 700 HP on pump gas....but of course you can go aluminum and take some weight off.

I've done a lot of 500-575 HP 383-400's for street cars and they are sweet too. Don't pull quite as hard....but very fun!!


JIM

 

There is a replacement for displacement. It's called modern engine design.

There are several on this Forum who went to a 383 before doing an LS-swap. I learned from their mistake, and am skipping straight to the LS and 5-speed manual swap.

Put that blown LS in the Vette! You won't be the first.

 

The only thing you can gain from a block upgrade is aluminum...weight vs horsepower.....all engines, given the same displacement and volumetric efficiency will produce the same power with similar components

 

I have a friend with a '74 vette, 383 stroker.
Engine dyno at 502 hp
AFR 195 heads, Holley 750 DP, Hyd roller cam.
Everything inside is forged.

Top speed ~170 mph
1/4 mi 11.6

Very streetable, not uncivilized.

 

Remember this.....the entire driveline needs to be able to handle huge horsepower and torque....if you intend to use it. The C3 Corvette driveline was not designed, nor will it handle using 700 HP or equivalent torque. You will blow out the rear end, the transmission and possible driveshafts.....IF you use that kind of power. You want that power,....its going to cost huge money to upgrade all those components....or you could just by a Chevelle or Nova or something that can handle it. In reality.....that kind of power is unnecessary nonsense for a street car.....if you drive responsibly on the street. Street racing is irresponsible. Drag racing....costly. Its all your choice...your money....and the conseqences are huge. I have wasted huge money to make better than stock power....and I am not sure it was worth it. The cost doesn't end even after you build all that power......guys on this forum keep building their engines over and over again....cause they destroy them with abuse. Not my idea of a good thing to do.

IMO......huge horsepower and torque is just for barstool bravado and guys who define themself by bragging about big numbers.....it has nothing to do with reality or real life use of the car on the street. Typical.

But......to answer your question.....I would pick a big block. Even a more mild build has torque adantages over a small block. I spent too much money on my 408 cubic inch small block engine, which is for sale on the Parts for Sale thread if you are interested........but I wish I would have just built a big block instead. Its all about torque ....and the big block delivers.

 

If you have a choice, go with the BB, as Jim has said it will fit

You are in full control of the go peddle,

Neal

 

400 to 500 hp is very fun...and affordable as a small block....not a big block

 

And my suggestion is to get a crate motor with a warranty. Im finding it very hard to find a good set of bearings for a big block currently. Just had 2 motors destroyed due to bearings seperating and failing

 

GM sells their 525 HP LS3 as a long block now:

https://www.chevrolet.com/performanc...ock-assemblies

Basically an LS7 without the dry sump. Find an intake that fits, and enjoy a GM warranty on an engine that may last 300,000 miles.

EDIT: Also $7K (though you need a few more things)
https://www.summitracing.com/parts/nal-19434648

 

30 month, 50,000 mile warranty
https://www.summitracing.com/parts/m...61ctc#overview

$7100 clams, smackers, shillings, washingtons, bucks....you know, the good stuff....

Heres a few more options for small block big displacement

https://www.summitracing.com/search/...rder=Ascending

 

And everyones favorite big block

https://www.summitracing.com/search/...l-396_7-0l-427

 

The borgeson and the small block is the way to go for street fun and the small block is way easier to work on but if your after big massive poer then a big block will fit the bill .

 

Stroker small block 383/427. Those engine bays are difficult to work on with a small block.

I’ve got a hot 383 and a Tremec 5 speed. (3.36 rear gears is the perfect combo)
Car is plenty fast, the Tremec transforms the car.
too much Hp and you’ll be upgrading the whole rear end.
I have the Borgeson setup. It’s tight with a small block. Bloody amazing steering though.

big blocks are the best though. Easy power. Just not in a tight space like a vette.

 

I am a small block guy........I have built many of both and still do....but for me, the small block gets the nod on the street, and here is why. The physical engine is smaller and lighter.....which makes it much easier to work on, a big block C2/C3 is ten pounds of **** in a five pound bag.........it is much less money to build, about 30-40% less.........and can easily be made to make 500 reliable street horsepower.......which, if you need any more than that on the street, it is just posturing......you have to have a lot of **** upgraded to make a C2/C3 Vette safe after 500 horsepower......so along with a Big Block comes added expense to hold the power.......IF, you decide to make 600+ horsepower...which is stupid easy to do with even a 468ci engine (.060 over 454)........even at 500hp, Drag Radials are really needed......anything else just spins on **** pavement......
I have a 406 in my 72'........I had a 69' 427/400 Tri Power car with a 4 speed.....the small block car would gap the big block car by probably 1.5 seconds in the 1/4 mile....but the Big Block car had that star power to wow the car show crowd......

Jebby

 

You do not have to spend anywhere near $20k to put a big block in. you can get one that pushes close to 600hp for under $10k (engine only)check out Vortecpro. all the info above is good advice. once you are close to or over 500hp you will need to keep street tires on it to keep from breaking parts south of the flexplate but it will be a lot of fun to drive

Pat.