C3 - Big block vs Small Block

[Glen C.]

I'm sure this topic has been discussed before and I just can't get the right search verbage so I apologize.

I'm starting to look at C3s and being a high schooler in the 70's my bias is the bigger the engine the better but can anyone tell me the pros and cons of the big blocks versus the small blocks in the early 70 cars?

Thanks,

Glen

[Tom H.]

Re: C3 - Big block vs Small Block

Hi Glen !

I've had both and I really do like them both. To just drive around and enjoy, the small block is probably the practical choice. On the other hand, there is nothing like turning the key and bringing the big block to life and taking a little cruise.

I guess so we can give you the actual pros and cons that apply to you, we'd need to know what your plans are with the car.

If you are buying a project, or a done car. Will you be driving it a bunch, or just using it for a garage trophy ?

Bottom line, regardless is buy the one you like. If you've been dreaming of a big block Corvette since the 70's, I can think of no downside down enough to tell you not to GO FOR IT !!!

[Glen C.]

Re: C3 - Big block vs Small Block

Good morning Tom,

Thanks for the response. I'm not looking for a garage trophy. I want something I can take out on weekends and enjoy. I want to find a car that's a good solid driver and fairly well sorted out so that I can enjoy while I'm working on it. My first car was a 1973 Z28 so I'm familiar with the 350. I've always wanted a 454 but with have no expierence with them. I'm not sure how they would handle the traffic jams in the Atlanta area from an overheating perspective.

Thanks,

Glen

[Tom H.]

Re: C3 - Big block vs Small Block

Hey Glen !

For me, I'd hate to be in a hot traffic jam in any old Corvette these days ! I think the 454 would be fine for you. Providing the car is in good shape and the cooling system is up to snuff, you'll be fine. It will get hot, but look at it this way. It's been getting hot for 30+ years. It will survive a few more cruises with you behind the wheel.

The only real drawback of a big block are the obvious. Parts can be pricey and hard to find, fuel mileage isn't great. ( Who cares. ) and the heat issue. But hey, they all get hot in summer traffic. Try a midyear coupe on a hot day sometime !

I think you would enjoy the big block. Just take the long way around and bypass that traffic jam !!

[Warren F.]

Re: C3 - Big block vs Small Block

If your search is for an early '70's Corvette, look hard for a 1970 model with an LS-5 engine. Torque was the highest of the 3 years with 500 ft lbs! When you drive one of these and put your foot into it, you'll receive a thrill or rush that will be very memorable and quite pleasing to your senses!

[Randy C.]

Re: C3 - Big block vs Small Block

My exposure to this experience is "dated" and might be due to inexperience at the time, but here's my two cents worth. I've had my '71 base engine automatic coupe with A/C since 1978 and it's never heated up on me, summer or winter, in traffic or on the open highway, to this day. On the other hand, a dear friend of mine had a '70 big block automatic roadster w/o A/C back in the mid-70s. It was great on the open road and it even got decent gas mileage (mid-16s/mpg). But, in town, it was a heat monster! Traffic was a killer for it, despite even a 160 degree thermostat. Again, the big block experience was a lifetime ago and I just don't know if there were any other issues with the engine that caused the heating problem in town, or not. I just remember that we took my car into town and his car on the freeway!
Randy C.

[Dennis S.]

Re: C3 - Big block vs Small Block

Glen
I grew up in the muscle car era and ALWAYS wanted a 427 vette, but could never afford one. Back then, most everyone believed bigger was better. Like they say, there is no replacement for displacement. If you had a bias for big when you were a teenager, then I am sure you still have it.

There is nothing like the torque of a big block when you stomp it. But remember, more fuel equates to more heat. Big blocks do generate more heat, so the entire cooling system has to be up to snuff. I pulled my original copper/brass radiator out and put in a Dewitts Direct Fit aluminum (30% better cooling they say) painted black for the discerning eye, and made sure all the radiator and hood seals are in place. The original radiator went into the box for storage and future delivery to the next caretaker. Even removed my front license plate holder to improve air flow. The fan clutch has been rebuilt, surge tank and heater core replaced and new hoses/belts/correct thermostat. The car now runs at 180 in Miami traffic. Before it tended to overheat and puke.

Buy the car you really want, the best car you can afford, because then you will be more inclined to do all the things to it that need doing. Believe me, all of these old cars need things done to them.

[Jim T.]

Re: C3 - Big block vs Small Block

Buy the C3 that will make you the happiest. The 70 454 does have some impressive torque compared to the 70's 350/300 with only 380. I have driven my 70 350/300 since it was new, 160,000 miles, and the best gas mileage ever was 22mpg on a trip from San Diego to Dallas. My 68 327/350 has less mileage, about 98,000 since new. Would have more but it is not air conditioned and air conditioning makes long trips and even short trips more enjoyable. If you buy a 454 and it does not have full time vacuum advance,heating problems in traffic will be reduced with full time vacuum advance and city driving gas mileage will be greater.

[Edward S.]

Re: C3 - Big block vs Small Block

I can tell you first hand - I had a 63 Coupe red/black, summertime stuck in traffic the interior heat was really bad. I have had a 425 65 Coupe for some years now yellow/black with original side exhaust system, once you get rid of the exhaust system being right below your floorboard what a change in heat. My car stays so cool that I never use the interior vent system. The only drawback with the side pipes is the noise, however you do save wear and tear on your radio by never playing it. The big block also passes everything but a gas station.

[Joe T.]

Re: C3 - Big block vs Small Block

Big Blocks are fun to drive and impressive to look at. I have a 1969 L36(390/427) and it was fun (and will be again, once it is back together). The biggest drawback to a big block is working on that horse! There is NO room in the engine compartment (I have A/C) and changing or checking the plugs and even the wires means getting under the car and removing the right front wheel. I wouldn't trade it for any small block, but then I am a glutton for punishment as well. One more item: My opnion is that the big block does tend to make the car a little nose-heavy for agressive driving into some corners, but that might just be me...Good luck and enjoy

[Mike G.]

Re: C3 - Big block vs Small Block

if you can find a 70 lt1 its the way to go. just as much power but less weight and better balance. great cars.

[Les G.]

Re: C3 - Big block vs Small Block

I own a 1970 350/350,I drove and looked at big blocks. They do run hotter and alot of the heat is transfered into the passenger compartment. They are also heavier in the nose so the small block handles better on back roads and around corners. They are also harder to work on due to clearances in the engine compartment. Like someone else mentioned if you want the best of both worlds find an LT-1 possibily a 70 or you can go for a 71 or 72 if the budget permits.

[Wayne B.]

Re: C3 - Big block vs Small Block

I haven't had a big block but I my 70 LT-1 gives me the best of both worlds smaller size with more than a horsepower per cube. I did help a friend change his spark plugs in his 454 once, now there's an all day chore I never want to do again, that engine compartment was designed for a small block and there just isn't much room to work. The BB does add 150lbs over the front wheels so the handling would be better in a small block but then again it depends on how crazy you're driving. As for heat, geez i haven't been in one yet that wasn't hot on that floor board.

[Thomas H.]

Re: C3 - Big block vs Small Block

I have a 71 LS5. I would have it no other way. I cut my teeth on big blocks, built several over the years and raced a few along the way.

When I got my C3, I was suprised how much heat is generated in the interior. My car does not have AC so it does get a bit "warm" when sitting at lights in the summer, but I can deal with it. Someday I may try the insulating stuff you put under the carpet. I have heard some folks have had good results using it.

Since I don't have AC, I don't have any issues working on the engine, except for the #7 plug and getting around the power brake booster, but it can be done. Only takes me about 30 minutes to go over the plugs when I do.

I did have issues with some overheating when in traffic, but that was resolved by replacing the original (tired) radiator with a Dewitts. The car rarely goes above 200 now.

My racing partner had a 70 350/350 which I drove a few times and I still prefer the big block, but that is just me and my opinion.

Find a car you like, and enjoy it. (but you'll like it better if it is a big block........)

Tom

[Ken K.]

Re: C3 - Big block vs Small Block

I have rebuilt a 70 LS5, a 72 LT-1 and a 73 LS4.
The big 454 is the best. For me the 73 is the best driving and it is the best of the seven Corvettes that I have had. Here is a link to my 73.

http://kens1973ls4.weebly.com/

Hope you find what you want.