kennedy759

I have a 97 base and am looking for a early c3 big block 4 speed to mess around with, not to concerned about appearance as long as the drive train is strong, looking at pre 1975, need to sell my 88 mercedes 560sl to fund this project. any thoughts? only big block I have owned was a 70 olds 442 conv 4 speed and it was a hoot and holler to play with. sold it for the mercedes.

Vetteman Jack

Maybe post your question in the C3 section?

baxsom

I've been inside my C3 454's engine a few times.

momo20

are you wanting to swap it into the c5?

JR-01

Stuffing a heavy, inefficient 70s big block and 4-speed in a C5 makes absolutely no sense to me. You would pretty much have to fabricate everything.

kennedy759

no, not going to put it in my c5, just want a big block stick corvette to play with, roar up and down the road with it, want it user friendly so it needs to be able to use unleaded gas.

c4cruiser

My first Corvette was a 1970 coupe with the LS5 454 with 390 HP and a 4-speed. Was a really fun car to drive in spite of not having power steering I added that after a year or so. I traded my '69 Road Runner and $1500 cash for it.

The rear end gearing was fairly high and it would easily hit 130 and more. The engine had tons of toruqe and it would light the rear tires in 4th geat at 30 MPH. I also added '69 big-block side exhaust just after I bought the car.

I don't recall what gas mileage figures were but being that I owned the car back in the mid-70's, gas prices were very low. IIRC, premium gas ran around fifty cents per gallon, if that.

With today's gas being unleaded and having something like 10% ethanol (maybe more in some areas) I would think you might have to pull the heads and have steel valve seats installed. Even 92 octane gas could be a problem with driveability. But these cars are around today and can certainly be made to run on today's gas.

I would expect to see prices in the mid-$30K range for a nice one. A friend just sold his '70 LS5 car for $34K. If you don't car about originality, maybe look for a decent C3 and do a swap. 454 motors are available and there's not a whole lot of work to do to in the swap.

JR-01

Oh.

LateBreak

Used to crew on a 69 Vette road racer. 468 BBC with dry sump and fenderwell headers. It was kinda cool and insanely fast, but I still have nightmares about working on that car.

They definitely look neat and are fast, but everything is extremely cramped with the big block in there. The cars themselves are not great, the rear suspension geometry is horrendous without some major rework, and the front end is not much better. We had to use 1" tie rod spacers to get the bumpsteer right.

That said, if you're looking for something to just flog on the street once in a while, have at it.

JR-01

Gas prices were not low in mid 70s after the Arab oil embargo in 74. Gas prices went from under 30 cents to well over 50 cents which was a huge jump when you consider the average wage was $3 bucks an hour and cars got 12 miles per gallon. It caused the end of the muscle car for years to come. You could pick up high performance gas guzzling cars like big block Vettes for pennies on the dollar. I wish I would have stocked up.

3boystoys

The 350+hp small black cars back then were more fun on the street. My last C3 had a 350/350 with 100HP shot of Nitrous for the occasional blast. Most of the original stuff that old needed different valve seats for unleaded gas or more modern heads (I used Edelbrock heads on my last C3). The old cars looked good but they drove/handled like a covered wagon compared to any Vette today. They are also HOT inside the cabin even with all the heat shields in place underneath and even if you add more under the carpet.

The 4 speeds seem like fun too BUT with no overdrive and a high numeric gear in the back, highway RPM are quite high (3-4K at 70mph). Gas mileage on mine was 10 on a GOOD day, they do use gas like no tomorrow and the Big Blocks are even thirstier.

If you can find a C3 that someone put a modern LSx engine and 5/6 speed trans, that would be FUN.

LateBreak

Now you're talking Cruising down the highway at 4k R's with loud exhaust gets old quick, especially at $4 a gallon....

phoneman91

The BBC C3s clutch pedal pressure can be very heavy and I would think that it would be tiring in a short time when driving in the city.

We are spoiled by our factory C5 hydraulic clutches.

Scooter70

That's what I ended up doing back in 2004. The car was fun on the street but it was hot (no A/C) and I really didn't drive it that much so I sold it last year. It was awesome on the highway with the 6-speed though. Even with 3.70 rear gears the 0.50 6th gear spun about 1700 rpm at 70mph.

3boystoys

Had 2 C3's the first one was an 82' with Overdrive and the Crossfire injection. Nice car, not a rocketship but nice, the 69' was fun but a convertible corvette with BLACK INTERIOR, YIKES, what IDIOT dreamed that up. I'll never have another vert with a block interior.

StatmanRN

Had a 73, it was a dog stock. I would avoid the 72-74 smog motors.
Also very front end heavy, bad understear.
Also, if you do make power, it will be hard to hook up, and if you do hook up you will quickly find the weak link in the drive train with an M4.
BTW unless you are concerned with originallity, swapping a BB is not hard at all.

always1961

My '73 has about 350 HP and it gets 10 MPG...Tachs 2500 @ 65MPH
It's fun around town and short trips. That's why I love my the C5 I just recently purchased.

baxsom

This. Mine has been warmed over to 400hp and 500ft/lbs of torque at 3000rpms. On stock size wheels and tires anything over 1/4 throttle will get them smoking. The open sidepipes really sound amazing though when you are cruising at 60 downshift and put your foot into it.

92GA

I've never driven a C3 that I've liked. Every one that I've drove had so many squeaks and rattles, that just turned me off. Never was a BB guy either, I always preferred the quick revving SB. The first thing I did on my 69 Camaro was yank out the 396 and drop in a 350.The car was only one year old when I did that. The mid seventys cars were all dogs, ruined by the EPA. Don't remember what year they quit putting the BB in the Corvette, but my BIL bought a 77 Vette that had a 350 in it. I drove it a couple of times, that thing was a DOG. We all thought the cars were fast back in the day, mid 60s to the early 70s but they weren't compared to today cars. I found some old slips from the track after my old 69 Camaro surfaced a few months ago. The guy that bought it wanted some history of the car. Anyways the car only ran in the 12.80s with a built LT1 350, and my buddies 61 Vette only ran 13.10s or so with a 327. My sons 96 Firebird runs low 10s with a SB and a powerglide.

The C5 is a great car!! Going to a C3 with a BB would be taking 10 steps back. Plus the C3s were butt ugly from 74 to 80. Not going to get much hp out of a BB with todays 91 fuel either. I've got a 77 TA with a Ram Air lll 400 engine in it, had to limit the total timing to keep it running right on pump gas. My stock C5 with a cai and cat back will put it down I believe. I know running down the road in the C5 at 1800 rpm compared to 3300 in the TA, is much quieter.