Small Block or Big Block - Team Camaro Tech
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post #1 of 26 (permalink) Old Dec 15th, 05, 08:14 PM Thread Starter
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Small Block or Big Block

I,m thinking of building a new engine for a 69 350 SS. Numbers don,t
match. I have a 350, and a 402. For the big block, I have 2 sets of heads
to choose from. 336781 or 6272292. The car is for street only, under
4500 rpm most of the time, but I want plenty of power. I,m trying
to decide 402 or 350-383. Any thoughts?
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post #2 of 26 (permalink) Old Dec 15th, 05, 08:30 PM
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Talking Re: Small Block or Big Block

If you have deep pockets go with a big block. If not a 383 is almost as good and you don't have to change all the other stuff you need to change to go Big Block. (going with a big block is not just simply dropping it in.)

69 Camaro -originally a LM1 car. 327, Edelbrock E-streets, hooker, DUI performance distributors, ultradyne cam, stewart, TRW etc. Vintage Air, AGR steering, Corbeau GTSII seats, 700R4 TPI transmission, 12-bolt w/Eaton 4.11:1
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post #3 of 26 (permalink) Old Dec 15th, 05, 08:36 PM
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Re: Small Block or Big Block

Sincew the car is already set up for a small block, I would stick with a small block.
perhaps a 383 would be good.

68 Camaro, 555 big block, Doug Nash 5-speed, 3.54 gear.
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post #4 of 26 (permalink) Old Dec 15th, 05, 09:51 PM
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Re: Small Block or Big Block

Personally, Id probably be using that big block. Granted, you will need to spend a bit of money to make the swap work, but the big block will be durned easy to build especially with the parts you got. With the factory 402, no questions asked Id run the stock crank and rods(With good ARP bolts) up to 550 horses or even a little better. And with the 781 heads(Which are great factory cast big block heads), Id mill them down a bit and use the right dome piston for around 10:1 comp or a tad more. You will have to CC the heads to find out what the chambers are. Usually, they check in around 119-122 and the typical oval port big block head will lose 1cc per .005 taken off(flat mill). Meaning, youd get roughly an 8cc reduction by flat milling them .040. Even with the 2.06 and 1.72 valves it will still do well. Bowl work could help a lot. And if you wanted to go all the way, bigger valves can help as well....they just may not be necessary depending on how much power you actually want.

From there, an rpm aluminum intake, 750 carb and the right camshaft will really bring this thing to life. You could use a lunati voodoo 276 camshaft and have a motor thats easily capable of 12's and descent street manners. If you wanted something a little more on the wicked side, their 402A3 solid is a nice cam. Its numbers are 243/251 at .050 110lsa and .586/.600 lift. This cam could definitely benefit from larger valves and 11's is definitely doable. It will be a little bit of a handfull. If you wanted a tamer solid cam, the 402A2 will be a fair bit tamer and still make plenty of power. Its 238/248 at .050 with a wider 112LSA.

If you want to equal that power in a small block, you would definitely be best to buy a whole new rotating assembly for durability purposes cause the small block stuff wont hold like the factory big block stuff. And if your buildin a 383, youve got to anyways. And of course, your not going to find a stock casting small block head that will compete with some of the better big block heads. Heck, a real well done port job on those 781's could net you around 315cfm worth of airflow......some of the top notch big dollar small block standard 23 degree heads make 280ish. Like the AFR heads and Race rite heads....both top of the line standard small block heads, but youve got to pay 1200 dollars or more for a set. And then of course they still dont always compete as well with your ported stock big block heads........and that can work out to be a good bit cheaper(working on the big chevy heads you already have). And a mild job on the 781 heads(nothing too crazy) should net similar numbers to these small block aftermarket heads...and since you already got em, depending on where you look you could have your heads set up for less than the cost of those small block heads.

Whatever you do, come up with a realistic goal(power and street manners) and from there you can have an idea of how youd really need to build either motor. And once you know that, you can do some pricing. You can often save money building the big block in some situations cause you can use so much of the stock stuff.....whereas much of the small block stuff has to go. Plus, there aint nothing like a big block under the hood. Hehe. Dont get me wrong, I like small blocks a lot too...a whole lot, but if I had the options right there in front of me to go one way or another, Id have a hard time passing on the big motor. Its a little different if you have to find a core to start with and find heads. Then the big block could easily cost more, but with both options readily available, a lot of times they cost pretty similar.

One final note, I might be overestimating your goals. If all you want is something thats say capable of low 13's or as fast as mid 12's...the small block would probably be the winner pricewise. You could go with one of those 900 some dollar vortec packages with the modified heads and manifold, cast crank(stock if you keep it a 350) cheap aftermarket rods and hyper pistons with a 268 degree cam(like a voodoo 268) and have a good driver that would probably make a 12.80 motor from a 383. Easy low 13's assuming proper gearing and converter. So keep your goals in mind when you do all your combo figuring and pricing.

Last edited by greg moreira; Dec 15th, 05 at 10:11 PM.
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post #5 of 26 (permalink) Old Dec 16th, 05, 05:31 AM
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Re: Small Block or Big Block

I'm a huge fan of big blocks but if you're comparing a 383 with a 402, I'd have to go with the small block. No offense to the 396 guys, they make good power, but I just can't see the sense in building a big block at that bore size. You don't really get the advantages of the big block valve and port sizes like you do at 4.250 and bigger. I really like bigger - the 502 at 4.470 is just starting to breathe good and they really inhale deep at 4.600. Go with an inexpensive smallblock setup, Vortec heads and you'll have more than enough power for your daily driver. My .02

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post #6 of 26 (permalink) Old Dec 16th, 05, 05:50 AM
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Re: Small Block or Big Block

BBC hands down! Not only do they make more power dollar for dollar, make more power while being milder, they increase the value of the vehicle, look better, draw a crowd at shows, etc.
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post #7 of 26 (permalink) Old Dec 16th, 05, 06:43 AM
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Re: Small Block or Big Block

Garret, Dollar for Dollar when swapping a 402 into a car already equipped with a small block? I'll have to respectfully disagree on that one -- I'd build a 383 personally.

Things to consider . . .

Weight of the engine (the SB is a lot lighter -- esp with aluminum heads)
Cost to convert the car from small block to BB (swapping to BB is expensive)
Cost of building the motor (the BB would probably be cheaper if using OEM heads and bottom end)

Just my opinion -- I suppose either should go pretty good.

ps. if budget is real tight the BB might be the better choice -- you should be able to junkyard source mounts and brackets to fit the BBC into the car.

E85 racer and E85 carb builder

68 Camaro, E85 powered 427" small block. 9.96 @ 133 MPH, 1.319 sixty foot on motor. 5.92 eighth @ 116 with a 1.42 sixty breaking beams with back tire on the bottle
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post #8 of 26 (permalink) Old Dec 16th, 05, 06:49 AM
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Re: Small Block or Big Block

Originally Posted by 40Coupe
BBC hands down! Not only do they make more power dollar for dollar, make more power while being milder, they increase the value of the vehicle, look better, draw a crowd at shows, etc.
As i always say...unless you want to be able to pop the hood and have people say "Wow, look at those fat valve covers, its a big block"...i would say go with 383 since your already set up for small block. I was in the same exact situation as you last year and was going to go with a 396 originally and ended up with a 383 instead. It came down to the fact that for me it was really just to say i had a big block and ultimately decided it wasnt worth it. Especially since you can get BBC numbers out of a 383. And add the fact that the BBC is heavier and doesnt exactly improve the handling of the car. Dont get me wrong i love BBCs but it just didnt make sense for me. Just some of the changes that would have to have been made to the car to go big block (for me): Change the badging on the side from 350 to 396, which involved fender removal or at least a lot of work loosening stuff up...then having to fill the old 350 badge holes repaint that area and put the new 396 badge on. Putting a big block heater box and core in...pain in the a$$. New springs, new radiator, new headers (mine were less than a year old) and various other small things. Everyones different and i know there are guys on here who have made the swap from small block to big block and wouldnt have done it any different. Just my opinion for what its worth.
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post #9 of 26 (permalink) Old Dec 16th, 05, 04:36 PM
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Re: Small Block or Big Block

Justify those weenie valve covers however you want. When I open my hood it jumps out and says a BBC lives here.....powerfull!

Side by side 2 equal cars, 1 SBC powered, 1 BBC powered....BBC is usually more valuable.

BTW- Todd Geisler ran 10.49 @ 127, with a 414 BBC, boat anchor oval heads, 10:1 compression and 3500 lb.

Last edited by 40Coupe; Dec 16th, 05 at 04:54 PM.
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post #10 of 26 (permalink) Old Dec 16th, 05, 04:49 PM
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Re: Small Block or Big Block

They may be weenie valve covers but its hard to pass up a well built small block. I went through the whole process a few years ago and decided I'll save the big block for a Chevelle. That said a 383 is hard to beat plus I like the small block handleing. For me I'm going 406+ this winter. I also like when you pop my hood you dont get hung up on the big block but you also notice the tubular control arms, R&P, Hydro-boost. Plus it just doesnt look so cramped.

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post #11 of 26 (permalink) Old Dec 16th, 05, 05:02 PM
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Re: Small Block or Big Block

Well I guess I will add my $.02 on a topic that will never really be agreed on. For your goal it makes no sense at all to build a big block and deal with all the other headaches of getting it to fit and work well. A nice 383 will put a lot of "mild" big block on the trailer. I have seen this first hand. Some people are impressed with fat valve covers, some are not. My little weenie small block sure draws a crowd as well.

If you get the performance bug the 383 will still fill your needs. Going low 12's or even into the 11's with a 383 is fairly easy. I went 11.90 with a hydrualic flat tappet cam, street tires and 3.42 rear gears, with a 383. I beat my fair share of big block cars. It's not always about cubic inches as we all know. This guy is looking for a STREET only engine. If the car was set-up for a big block I would say go for it. Since it is set-up for a small block it just WAY more pratical to stick with a small block. There are also some pretty BIG small blocks out there these days so don't let the "skinny" valve covers fool you.

The big vs. small block is almost as bad as Ford vs. Chevy

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post #12 of 26 (permalink) Old Dec 16th, 05, 05:08 PM
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Re: Small Block or Big Block

Let me state it one more time: dollar for dollar, lb per lb, BBC's just make more power. Take a cast crank 2 blt main, 3/8" rod, oval port, tow truck BBC and go run 10's. Try that with stock SBC parts.
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post #13 of 26 (permalink) Old Dec 16th, 05, 05:12 PM
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Talking Re: Small Block or Big Block

I really truly love big blocks, but the 327 is just the sweet spot if you ask me. It is an excellent engine. The rod ratio is awsome so it runs smooth and makes good power. A few less cubes is ok. My next choice is the 377. A destroked 400, using 350 crank and rods. kind of a gas eater but talk about a fun engine, that can be wound up to 7 to 8 grand all day long. I love a reving small block and they are just as impressive as grunting big block. Nothing like the sound of the big block grunt though!! Which ever you choose, make sure you match parts and build what "YOU" need and want. Nothing is worse than unexpected over kill or the disapointment of not enough of everything. Think about what you want out of it. Write it down and ask lots of questions here at TC to help make the right choice.

For heads if your not concerned with factory looks then go with Vortecs if the small block is your choice. You can not beat the bang for the buck. I bought "EVERYTHING" and a cam, rockers, nuts,bolts gaskets, intake, everything needed to convert to vortecs for $990.00 from Salle Chev in Portland including shipping.

One More thing:
That fat big Rat sure looks good when open the hood!!! Wa hoo a big block Camaro!!!!

Good Luck and happy hunting.

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Then, you have enough horsepower."
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Last edited by Joe Harrison; Dec 16th, 05 at 11:27 PM.
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post #14 of 26 (permalink) Old Dec 16th, 05, 05:47 PM
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Re: Small Block or Big Block

Originally Posted by 40Coupe
Let me state it one more time: dollar for dollar, lb per lb, BBC's just make more power. Take a cast crank 2 blt main, 3/8" rod, oval port, tow truck BBC and go run 10's. Try that with stock SBC parts.
Yes, stock vs stock, but thats really not what were talking about here. We know that 383s are built to run. And....vavle covers may be "puny" but i would line my car with a 383 up against a lot of 396 cars and have no problem beating them. Just ask my buddy with the 71 Chevelle SS 454.
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post #15 of 26 (permalink) Old Dec 16th, 05, 07:28 PM
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Talking Re: Small Block or Big Block

The big block may be worth more if you charge by the pound.The BB looks good under the hood. I often complement my Big Block Buddies on their valve covers, and they tell me how much they like my tailights! If big blocks increase the value, i'm gonna snatch out that "rat killer" in mine and put in one of those SUPER-GINORMOUS caddy 525's. Back to the point...weigh your options, decide how much power you want to make, your budget, the general theme of your car, and handling. Either engine has the potential to make good power.I like both the big block and the small block. Do your homework, it will pay off in the long run.
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