VCCA Home Forums TECHNICAL - 1945 AND EARLIER Chevrolet Speedsters Transmissions for Speed and Sport

The transmission behind the Chevy 4 has a less-than-stellar reputation for strength and driveability (it’s a crash box). I know of fellows who have put Volvo four-speeds and modern GM five-speeds behind them, but some of us want to stay period. Are any of the “big car” (Buick, LaSalle, Cadillac, etc.) transmissions from the era worth adapting? What about six-cylinder Chevrolet tranmsissions? Any period options for overdrive out there?

I’d love to hear some thoughts.

-Dave

Can't say much for the others but I would stay away from the Buick. I know guys that had them bolted to the nailhead V8 and they would not hold up at all. They were from the Roadmaster also.

Woha, but even the smallest Nailhead is still producing something like 140 horsepower; a far cry from the 90 or so a really hot four might produce.

-Dave

I think you might be surprised and find you can get much more than 90 hp out of a Chevy 4. Not sure what HP was produced by the Spurgin-Giovanine racer but with top speed exeding 125 mph it must have been more than 90.

The nailheads were stock. One was in a 32 chevy and the other one was in a 36 chevy. Every time they really got on them the gears would go.
Back in them days I had a 32 plymouth with a 53 chrysler hemi. I bolted a 36 dodge truck trany and it never broke.

Good thought. It made me do some research and I found this here: “For the 1948 season...estimated power output was around 150 bhp”

I am surprised, but then we’re talking about a full-race engine. How long would such an engine realistically last on the street? I still think 90hp is as much as you’d want in a speedster, and I’m shooting for more like 60- or 65hp.

In all fairness, though, I didn’t specify that. The Spurgin-Giovanine engine in a drag-race setting (as opposed to the dry lakes where cars get a push start and aren’t really hammering their transmissions) might very well destroy an early-”˜30s Buick transmission.

I'm not aware of much historical precedent for hot, road-going Chevy fours. T guys swear by their crazy planetaries, and A guys tend to go for the ”˜39-type transmission. In that vein, I guess it's a question of beefing up a '28 three-speed (which I don't have, but could get), or looking into whether a late-”˜30s Chevrolet floor-shift box will bolt to the four-cylinder bellhousing.

-Dave

Those all sound like very cool cars! I once saw a snippet of a circa 1954 article on swapping a 322 Nailhead into a '49-'52 Chevrolet coupe and thought that sounded like a great combination.

-Dave

You might contact Dick Bertolucci in Sacramento CA. He has been an old Chevy hot rodder for many years. Can tell you what many of the guys did in the 40s and 50s to get the Chevy 4s to go fast.