Scuzz Grimsley and Spaceman Lee, cheerful southpaw eccentrics, have found a home in the left-handed clubhouse of the almost first-place Montreal Expos.

"Flakes and wackos . . . we got a whole team of 'em . . . This is what you call a 'wide-open': clubhouse - anything goes," beamed 20-game winner Ross Grimsley.

"We're baseball's secret. Word of the Expos stops at the (U.S.) border."

"Any team with five left-handed pitchers is going to be different," imparted Bill Lee, who escaped from Boston's Fenway doghouse to the standing ovations of Canada's Olympic Stadium.

"There's more laughter in this locker room in 30 minutes than you'd hear in a month with the Red Sox, where everybody just stares straight ahead into their own cubicle."

Suddenly, lefty Rudy May, who had been quietly lying on his back in the middle of the clubhouse beating his chest with both fists, leapt to his feet and grabbed a long knife out of a birthday cake.

"I'm going to cut your throat, Carter," May said to catcher Gary Carter.

Thus began May's well-known blankstare imitation of a homicidal Maniac. Well-known, that is, to teammates, but not to Expos visitors who think they are about to witness an assault between the battery.

May, the mock murderer, blends in nicely with Lee, who is doing his yoga exercises, and the diabolically mischievous Grimsley, who earned his nickname because he always looks like he ought to be plotting some "scuzzy" escapade.

The Expos don't just have lefthanded pitchers - e.g., Woody Fryman (1.89 ERA) who waited until he was 39 to discover he was a natural relief pitcher, or Dan Schatzeder, who says, "I'm tough to scout . . . nobody can pronounce my name."

Montreal also has left-handed thinkers - e.g., the eminent outfield of Ellis Valentine, Andre Dawson and Warren Cromartie.

On a recent evening, all three were screaming at each other in front of their lockers. The topic under debate: When you jump, which part of you jumps first?

"Now that's my kind of discussion," said Lee.

The young firm of Valentine, Dawson & Cromartie is typical of the Expos - gifted, erratic and muddled in the public mind.

"At a baseball banquet in Baltimore, I asked the whole crowd to name one Expo outfielder," Grimsley related. "Nobody could.

"I told 'em, 'Well, folks, it's the best outfield in baseball.'"

As might be expected, the Expos, at or near the top of the National League East all season, are something of a mystery - even to themselves.

"This is a streaky team with two totally different identities," Lee appraised. "We're awesome at home (17-3). We score early and often. On the road . . . well, we do some strange things. Maybe we need to have everybody switch positions."

The home-road split personality can be traced to another form of Expo schizophrenia - young, coltish regulars and old, savvy pitchers.

Few teams have a lineup of such imposing physiques as Montreal. Yet those conspicuous musclemen are misleading. It is primarily the junk-balling pitching staff - with the NL's lowest walk and strikeout totals - that has Montreal in contention after 11 years in a sub-500 wilderness.

"We're not always consistent, but our talent makes up for it," said Grimsley. "We need more clutch hitting and less mental mistakes. Each year we get better in those areas.

"Maybe we won't win it all this year or next. But this is the coming club in the National League. It won't be long before this is a powerhouse."

The Expos have the perfect manager to make inroads into that traditional flood of Expos mental blunders - stern Dick Williams with his bristling, flinty stare.

Yet even William cannot totally tame his young horses.

On Saturday night here, for instance, Valentine became confused between bases and made it only to second from first on a hit that bounced off the left-center-field wall.

Left fielder Cromartie topped that. Twice, he tried to gun down runners at second base. Twice his pegs reached the first baseman - on the fly.

But center fielder Dawson pulled the pip. With the bases loaded, he broke back on a shallow fly. Then, after redirecting himself, he pulled up short instead of trying for a still possible catch.

Trapped betwixt and between, Dawson watched the bloop bound off the Astro-Turf and over his head to the wall for a three-run tripple that turned the game irrevocably against Montreal.

In true Expos fashion, Valentine forgot to back up the play. But when he finally ran the ball down on the center field warning track, he unleashed a magnificent leave that traveled 340 feet, reaching home on one bounce.

While the Expo run production languishes in the bottom half of the league, its staff ERA is second best.

"If Steve Rogers ahd spent the last five years with a winner, people would know he's the best pitcher in the league," Grimsley remarked of his mate who was only 13-10 dispite a 2.47 ERA in 1978.

"I know how he feels. Nobody knew I won 20 last year."

The future is all before the young Expos.

If those curve-balling vets of left-handed persuasion, Scuzz and Spaceman and the rest, can piece together vintage sludge-ball seasons, and those young gazelles, Valentine, Dawson, Cromartie et al., can acquire some of the stoic calm of veteran Tony Perez, that future might begin to look a great deal like the present.

"These are great days," said Lee, who last week celebrated pitching a shutout by shaving the chest-length beard he had grown since he was taken out of the Boston rotation last August. "I put the whiskers in an envelope and mailed them to (Red Sox Manager) Don Zimmer."