"New" transmission - WOW

[Lobo'74]

I've had trouble with my stock clutch and stock 3 speed for the last couple of years. Sometimes it won't go into reverse, sometimes it will get stuck in first, sometimes it engages with a loud, metalic, "Thunk" that reverberates through the bed. Feels loose and sloppy. It turns out 3 or 4 fingers on the stock pressure plate were bent. My shop said they didn't even know how it was shifting at all in that condition.

Replaced the clutch with a Centerforce II and a new Centerforce II pressure plate. Found a racing shop up in Wisconsin that makes Saginaw trannys for street and circle track applications. Got a "one line" Saginaw 4 speed for street use from them. The "lines" refers to lines cut around the 10 spline input shaft for identification of the various ratios available. The "one line" ratios are: 2.54/1.80/1.44/1.00. They called it a close ratio, I have seen it described as a "wide ratio" in another site online. I know that Chevrolet put them in Camaros, Chevelles, and even in some Corvettes, It was the factory close ratio 4 speed unless the old "rock crusher" type Muncie was ordered. (according to various internet research sites).

My local mechanic said this one was stronger than a Muncie (I have some trouble having absolute confidence in that assesment) and the Tranny shop said the "one line" was as strong as a Muncie. I just know that a salvage Muncie runs $900 - $1000 and up around here (central VA), if you can find one, then you need to get it rebuilt. This rebuilt Saginaw transmission was $545. Put Royal Purple 75W90 fluid in it and got it and the new clutch installed.

Put in a new Hurst shifter. I picked the one that was closest to the hole in the floor for the existing Fenton (an OLD Hot Rod name) 3 speed shifter. Turned out the shifter for the '67-'68 Camaro was it. Shifter sits more towards center of the tranny tunnel than the old one, but not out of reach.

WOW. What a difference in driving. I just took it out on the highway for the first time (completed install two days ago, completed floor redo yesterday). Smooth, crisp operation of the clutch and the tranny. Drops a very consistant 1000 rpm each gear (may be a little off from 1000 exactly, but close enough for me). Exactly the operation I wanted. On top of that, much lower RPM in 4th than the old one in 3rd. Both were 1.00 to 1 final drive ratio, so it should be the same. Old 3 speed was 3000 - 3200 rpm at 70. "New" 4 speed is 2600 - 2700 at 70. Shoot, at 55 in 4th I'm under 2000 rpm. I figure the old clutch was so bad that the slipage there was a problem, and the solid grip of the Centerforce II delivers more power to the transmission, so lower RPMs at the same final drive ratio. This is with a 4.10 (or 4.11, not positive which) rear end, and 31" tires. My reasoning may be off, but thats my best explanation for the drop in RPM.

Can't wait to get the 450 - 500 miles Centerforce requires for break in before going full throttle. THAT shoud be a rush . . .