67 427/400 with powerglide vs M21 4spd?

[jack katz]

O.K. Here is my dilema....I've got a line on a 67 427/400 with powerglide., a/c and lots of other options including the A.I.R. system. The numbers match, and the tank sheet is still on the tank...it truly is a survivor!

The question is that I don't see much about the powerglide transmission on this NCRS Tech Discussion Board, and I'm worried that if I ever have to get the Powerglide worked on that it will be tough to get parts, or get it serviced! Is the Powerglide considered a reliable transmission as far as Chevy / Corvette transmissions go? How does it perform compared to a 4 speed (comparing a 3.08:1 4 speed, of course since that appear to be the only combination available with the 427/400 Powerglide). I know it won't be the same, since its a 2 speed automatic, but will it have the same "get up and go" from a standing start? Will it still feel like a Corvette?

[Mike M.]

Re: 67 427/400 with powerglide vs M21 4spd?

Drag racers who elect to go automatic and are on a budget prefer the old alum case powerglide such as in your potential new vet. a properly tuned 400 hp with PG will nail you and your lovely into the seat backs. go for it if it truely is a Bowtie candidate(survivors don't exist in NCRS good luck, mike

[Ed Jennings]

Re: 67 427/400 with powerglide vs M21 4spd?

There is nothing inherintly wrong with a PowerGlide transmission. Millions of passenger cars got by just fine with them. In a Corvette, given my choice of a 427/400 PG or a base engine 4 speed I'd take the 4 speed. Not that the 400/PG combo won't perform. So would the C5 automatic that I just sold. Just something about an automatic and a Corvette that don't go together. Just my 2 cents.

[Mike Cobine]

Re: 67 427/400 with powerglide vs M21 4spd?

In a full size Chevy with a 3.55 rear, a small block and Powerglide would rev like crazy to around 55 mph, then suddenly someone pulled 6 plug wires off.

Granted, the Corvette is a bit lighter, and the 427/400 has a lot more torque than a small block, so you won't be losing 6 plug wires, for sure.

But it will never perform like a 4 speed, or the Turbo 400 and Turbo 350.

It will be more car than you have probably driven or you wouldn't be asking this, so you won't be disappointed in those random and impromptu rushes.

In most stoplight grand prix, you will have all you want, as you'll get to 55-60 faster than you thought possible. And few really run faster than that from a stop light if they want to live, don't want to kill anyone, and want to keep a license more than a month.

However, the real point here is the aim you have for your car. This car is one that survived, and deserves to be kept that way, and preserved. It is a hot rod, but it isn't as it is an antique.

A lot of hard runs behnd a 427 will scatter that Powerglide like confetti in New York on a parade. There is a reason that the Turbo 400 came out nearly the same time as the 396 in '65, although the Corvette didn't get it due to lack of room in the tunnel.

If you want some fast cruising, impromptu stop light runs, and going fast through the gears a lot, you probably are not really into the spirit of restoration and preservation and would be better off buying a nice old Corvette with an NOM and a few mods that you can do what you want with it.

This car begs to be kept the way you have it, with cleaning, care, and constant attention to obtaining original parts for any that are missing or for those that wear out over time.

[Bill Stephenson]

Re: 67 427/400 with powerglide vs M21 4spd?

-------The few 66 big block Powerglides and the 67 big block powerglides had a specific HD trans designated for them.They would take a tremendous amount of abuse without a problem...........Bill S

[Michael S.]

Re: 67 427/400 with powerglide vs M21 4spd?

Buy it and drive it to death! The automatics are OK, I've got several. If you do not like the performance of the powerglide and are willing to do a "bolt in" that will really be nice, install a 200R4 automatic overdrive transmission. It will "bolt right in"!!!. Have a deep (3.27) first gear and a tall (0.68) overdrive fourth gear. No cutting anywhere on the car, bolts right in the car in place of the powerglide. Only difference is you have to hook up the "TV" cable to the carb to make it shift properley. Remeber, a powerglide also has a rod to carburator to control the transmission. No one but you will know it has been installed. Performance and drivability increase is astonishing! Will a 200R4 hold up? Buy the right one from a Monte Carlo SS or better yet a Buick Gran National. 200R4's hold up in 9 second turbo Buicks. It will do fine in a 400 Hp Corvette cruiser.

Go ahead and modify the car, it's just another old car!!

Mike
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